Gibraltar Museum



The Upper Rock, Windmill Hill and the Europa Flats


The following article has been extracted from the 1999 book ‘Gibraltar at the end of the Millennium: A Portrait of a Changing Land’ by Clive and Geraldine Finlayson.


In the first Chapter we saw how the vegetation around Gibraltar changed in response to climate changes during the Pleistocene. Then, the climatic amelioration after 10 thousand years ago promoted the development of the Mediterranean woodland and matorral that we described in Chapter 2 and it was then that humans probably first began to actively modify the environment. In Gibraltar this may well have been minimal as we discussed in Chapter 2. So it is very likely that the vegetation which grew on the Rock when Tarik landed in 711 AD, and for a significant time thereafter until Al-Mumin’s Medinat was constructed in 1160 AD, may well have resembled the ancestral climax community of the Holocene climatic régime. We can with some degree of confidence take the vegetation described in Chapter 2 as our baseline and the best illustrated of the climatic conditions that prevailed prior to human interference and were we able to reverse the many individual historical events that have changed it since. This chapter is precisely about the changes since medieval times. We have seen some of these already in Chapters 3 to 5 and we will discuss others in the next Chapter. Here we focus on an area of Gibraltar which has been our “little garden” since our childhood, where we learnt our trade and the place which has given us more joyous moments than any other – the Upper Rock.


When you go to the Upper Rock now the general impression which you get is of lush vegetation with many trees and a dense undergrowth. With the exception of a few firebreaks, which are maintained, and some abandoned watercatchments the impression is indeed accurate. This image of “natural” splendour and beauty is far from pristine, however, and it is indeed the product of this century! The vegetation of the Upper Rock is today dominated by typically Mediterranean native shrubs, some of which grow to tree-like dimensions. This vegetation is a mosaic, a patchwork of plants of many species which occur in different parts in different proportions according to a mixture of factors such as soil depth and composition, humidity and indeed the presence of other plants. It is a historical landscape which has its base in the native limestone-loving plants of the western Mediterranean. Among the dominant plants are the wild Olive and the Lentisc which, as we saw in Chapter 1, have been in the area for at least 50 thousand years.


To understand the present-day landscape we have to go back and see how historical events modified the pristine Holocene landscape which Tarik may have seen into the Man-induced landscape which is the Upper Rock at the end of the millennium. We start, of course, with the Muslims who were the first to build on the Rock. Unfortunately we have little to guide us other than accounts of constructions. From our perspective the building of the Castle, City and Atarazanas of Gibraltar (Chapters 3 and 7) affected areas which may properly be defined as outside the present limits of the Upper Rock and which are dealt with in these chapters. We can add here that the slopes upon which the castle and the old town were built would have been covered in native vegetation which must have been largely destroyed by construction although, if later Spanish accounts are to be believed, the precinct of the castle (the Qasbah) contained a small forest where it was possible to hunt rabbits and the occasional deer (Chapter 7). Since much of the early development of the town took place in the lower, less steep, slopes which were covered by the red sands (Chapter 4) it is unlikely that this would have had any major effect on the natural vegetation of the Upper Rock. We are left with speculation although it would not seem unreasonable to suppose that the local Muslims of Gibraltar may have collected firewood from the Rock and grazed goats on it, with the consequent damage to the vegetation. It is also possible, as some authors have proposed, that trees may have been felled and used to build or repair ships in the atarazana or even for export to North Africa. Operations such as these, if they took place at all, would have been clearly limited in scale given the small size of the Rock.

After we had written these lines, in August 1999, we found a rich level of occupation in a cave on the Upper Rock that contained 14th Century Muslim ceramic and the remains of many goats! This confirmed our thesis that goats had been grazed on the Rock since Medieval times. For reasons of security we must, for now, keep the name of this cave to ourselves.


The truth is that, no matter what authors may have speculated about the history of this vegetation, we really do not know in what state the Upper Rock was inherited by the Spaniards from the Muslims in 1462. Had it been deforested by the Muslims or was it still in a primitive state? Certainly the sketches of Anton van den Wyngaerde (1567), which are the earliest available to us, give the impression that the Rock is already at that time rather devoid of vegetation. This could be the author’s interpretation admittedly but the scene is repeated in his two sketches which are extremely detailed and accurate and which show trees in some areas. So why would he leave others out? Why should his sketches, and indeed those of Bravo in 1627, resemble so much others of the Rock in the 18th and 19th centuries and indeed photographs of the 19th and early 20th centuries? In his sketches the areas of the Rock which seem to be most heavily vegetated are from Rock Gun to Middle Hill and to a lesser extent down to the old Willis’s Battery, the slopes between O’Hara’s Battery and St. Michael’s Cave, the lower southern slopes from Sandpits upwards towards the Rock and some of the lower slopes in the vicinity of the vineyards. This ties in well with Portillo’s description which is the first that is available to us. He mentions the southern limit of the red sands, as we saw in Chapter 4, by the “huertas de arboledas” or groves (orchards) of trees, exactly where Wyngaerde draws them.


John White describes this area in the mid-18th century:

“Between the South Barracks and the Naval Hospital is situated the most beautifully romantic spot in all Gibraltar. It slopes to the South-West, and is most effectually screened from East by the rock in its highest part, and from the North by the eminence whereon the South Barracks are built. It contains variety of good natural soil, and has been occupied many years by an honest worthy native of the place, whose skill, sagacity, experience and industry have long entitled him to universal esteem and goodwill. It is to the unremitting labour and assiduity of George Picardo that every table is indebted for the most valuable productions of the garden at all seasons of the year, and he has introduced a spirit of cultivation and improvement totally unknown before in this latitude.”


Portillo also tells us that there were wild olives on the Rock, which suggests to us that the entire Rock was not covered by them. Then he gives us a very telling remark when he says that these olives were not cultivated, even though there were some with good fruit in the vineyards, because the inhabitants used the abundant fish oil instead. So cutting them down would not have been a concern in those days. To this we can add a further clue – Portillo chose to highlight the wood inside the castle which seems to indicate that woodland was a rare enough feature of the landscape to be worthy of note where it was found. This woodland is clearly depicted in Bravo’s plan of 1627. Further references to vegetation by Portillo concentrate on herbs of medicinal or culinary value, many of which are typical of open ground, without further mention of trees other than to say that there was a high diversity of trees and shrubs in the district of Gibraltar, which included a great part of the hinterland of the Rock, and which is therefore unhelpful. He does not mention, contrary to erroneous attributions by some recent authors, Carob Trees. There are good reasons to believe that the lower slopes of the Rock, at least, had been heavily transformed in the early 17th century days of Portillo. He mentions Prickly Pears on the red sands and also tells us how they were used as fences in the vineyards. There were also orchards with fruit trees among which was the Church of San Juan el Verde which was run by the Knights Hospitaliers of Malta. There were other buildings lower down too, such as the chapel of Nuestra Señora de los Remedios overlooking the Caleta de los remedios, now Rosia Bay. Prickly Pears would not have grown well in woodland. Given that they came from the new world, their spread on the Rock must have taken probably less than a century! Wyngaerde’s sketches clearly show Charles V Wall running up towards the top of the Rock. This wall was built by the Italian engineer Calvi in 1552 to provide for the defence of the town against invading pirates from the south. It is inconceivable that its construction would not have been accompanied by the complete removal of all vegetation for many metres on either side, inside to allow the free movement of the defenders and outside to make the approaching enemy clearly visible at a distance. No cover would have been left for them to hide. Is it therefore coincidence that it is the areas on either side of this wall and around the castle’s walls that appear most barren in Wyngaerde’s sketches?


Matthew Bishop has provided us with an account of the attack by Spanish troops on the 11th November 1704. These troops were guided onto the Upper Rock along a path on the east side by a local Spanish Shepherd, Simon Susarte. The accounts suggest that they crossed the ridge where Middle Hill is today, after which incident a Middle Guard was established and the shepherd’s path erased. Some authors, such as Ayala who wrote a long time later and who could not have had first hand knowledge, state that the five hundred or so Spanish soldiers hid in a wood of Carob trees near to St. Michael’s Cave, others say in the cave itself. Returning to Matthew Bishop, he tells us that a company from his ship was ordered to the Garrison to assist in repelling the attackers and he says how, as his boat approached the shore, he could see the Spaniards on the hill and he tells us how they rolled rocks down. How could he have seen this, or the Spaniards rolled the rocks, had the Rock been covered in trees?! Here is an extract of his account:

“The morning we got thither, the Spaniards were discovered that came up the back of the hill. Then there was a command for twenty of our men to go on shore with firearms. I was glad to hear that I was picked upon for one and the sailors, hearing that I was to go, were all eager for going. They knew me well versed in the affair, as I had been upon a like expedition before. When the officers had determined who should go on shore, we got into our boat, and made all the haste we could; for we had them continually in our eyes. We were all in high spirits and fit to do execution, not being at all daunted at their numbers; for they were like swarms of bees upon the hill, and in great confusion, and we like lions in the valley seeking whom we might devour, as our duty required. At it we went, loading and firing as fast as we could. Our men had a great advantage of the Spaniards in firing up hill, and it was a very great advantage they were not obliged to wade; for the water often overflows that part where we were obliged to engage them. We were happy enough in missing that tide; had it been otherwise, we had been put in a bad situation. The Spaniards rolled pieces of rocks down the hill and wounded a great many of our men, our advantage in firing was more than all they could do.  When they found they could do no good they laid down their firearms.”


The destruction of the Upper Rock landscape continued in the 18th century. Ayala complained of the damage that the British had caused to the Rock by making it unassailable and, although this was undoubtedly true, the romantic view he had of the Rock prior to this appears to have been unfounded. There is no doubt, however, that major works were done by the British throughout the 18th century and that these flattened what little vegetation was around at the time of the capture in 1704. One early account is that of Robert Poole who visited Gibraltar in 1748. We can glean some useful information from it. Poole visited the vineyard, clearly a popular place for all authors, and highlighted the single Locust (Carob) Tree that grew there. Francis Carter (1777) who was in Gibraltar between 1771 and 1772 also mentioned this tree, which belonged to a species which had formerly been plentiful all over the hill, which was the only one left in Gibraltar! Carter also says that these trees concealed the Spaniards near St. Michael’s Cave when they attacked in 1704. Given the descriptions of that attack above we can only conclude that, assuming Carter had good sources, these trees were in 1704 already restricted to copses or small woods. Why, otherwise, would these troops have moved from Middle Hill to hide near St. Michael’s Cave only to retrace their steps towards the town in the morning? By the middle of the 19th century access to the Upper Rock had improved and Kelaart in 1856 commented how:

“Bridle-paths are cut out of the highest parts of the Rock; the Signal Station, and even Rock-Gun and O’Hara’s Tower, may be reached on horseback with perfect safety.”


He also mentions the “Mediterranean Stair”, nowadays called Mediterranean Steps, which had been cut out of the solid rock.


From Poole’s account we also see that the introduction of exotic plants had continued from Spanish times. The Prickly Pears were still in the south as were Palm trees, presumably from Spanish times but perhaps from even earlier or later, brought by the British from North Africa. He also mentions the Aloe which, from his description, was the Agave. This is another American exotic which must have arrived in Spanish times. These exotics seem to have become established on the lower slopes and there is no mention of them on the Upper Rock. Several authors mention, however, the Palmetto on the Upper Rock, especially near St. Michael’s Cave. The Palmetto is the Dwarf Fan Palm, the only native European palm and one which has probably grown wild on the Rock, the rocky terrain suiting it well even today. Some of the stands of this palm on the Upper Rock, especially on Mediterranean Steps and the areas around O’Hara’s Tower north towards the Cable Car Station and down the western slopes, are the finest and best preserved that we have come across anywhere in the southern Iberian Peninsula. In Spain these palms are regularly cut back to recover the soft hearts which are consumed. This practice is not traditional on the Rock, however, and the palms or palmettoes have been allowed to develop with their splendid trunks, truly one of the major features of the Upper Rock. Kelaart described these palms in this area of the Rock and contrasted it with the less-vegetated areas to the north:

“There is scarcely any wild shrub or cultivated plant to be seen, and the rock has here a more barren appearance…”


Much of the Rock was barren by the time Poole visited it in 1748, the last remaining trees having been cut by the soldiers encamped on the south-western shores of the Rock during the six-month siege of 1727 when according to James the men were given permission to cut wood for fire and took the permit to its full levelling the whole! Some recent authors have taken this to be the point when the vegetation of the Upper Rock was removed. Anyone who has tried to cut back undergrowth on the Rock even today, and we did that frequently in the 1970s and 1980s when we would clear rides in order to place mist nets to catch and ring migratory birds, will soon realise the effort and degree of difficulty involved. To endow a few regiments with the powers to completely remove all the woodland of Gibraltar in the space of six months is completely unrealistic. Clearly these soldiers removed much of what was left in 1727 including, it would seem, the remaining Carob trees except one! The deforestation had started long before and continued after 1727 for much of the 18th century as slopes were scarped and new batteries erected. Poole tells us that there were places in which the rock was almost bare, a situation which must have been worsened during the hot and dry summer months. To emphasise the point Francis Carter tells us that bushes on the Rock only survived in the most inaccessible places:

“where the barbarity of our modern engineers could not reach.”


So the cliff may have acted as refugia for native vegetation. He described the Rock as barren, not a tree nor a shrub to be seen above the town due, in his opinion, to the modern policy of the military gentry. There were some “greater and smaller cattle” but not many because of the shortage of pasture the provision of sheep, cattle and other animals being brought in plenty by Moors from Barbary. There were sheep, cattle and goats dispersed on the Upper Rock at the time, however, and they must have kept any prospect of developing vegetation down to zero! Kelaart considered that this depauperate state of the vegetation affected the micro-climate of Gibraltar and considered that George Don’s (Lieutenant Governor of Gibraltar from 1814-32) plans to plant trees on the Rock should be extended:

“On returning into the garrison, from a ride on the sandy beach outside the barrier, the difference in temperature is painfully felt. In passing the Puerta de Tierra, blasts of heated air oppress the rider, and on entering the main street, he again experiences the indescribable sensations of breathing confined and impure air. The summer nights retain nearly all the heat of the day, there not being sufficient time for the rock to become cool before the sun rises again. The reflected heat from the rocky surfaces of Gibraltar is of itself a great source of suffering to the inhabitants.

The vegetation on the rock being comparatively of a diminutive kind, does not afford much shelter; and I am sure if General Don’s plan was still further carried out, by planting more poplars, firs, and bella-sombras on the higher parts of the rock, Gibraltar might be rendered a cooler residence in the course of years.”


Domestic animals were not all that the “Moors from Barbary” brought. Barbary Partridges and Macaques also came in the consignments and were let loose on the Upper Rock. The tradition of these two North African species in this European outpost stems from these 18th century introductions and monkeys were still being brought to market at the end of the 19th century. The partridges in particular would have fared well in the open, stony, habitats of the Upper Rock then. This species must have declined significantly in numbers during the 20th century as the vegetation developed on the Upper Rock and the areas of low, stony, vegetation on Windmill Hill are nowadays their stronghold.


In Spanish times Windmill Hill was the Upper Tarfe, the Europa Flats being the Lower Tarfe, the name having clearly an Arabic origin. The nature of the vegetation on Windmill Hill is unclear but it seems to us that the rocky nature of this and the Europa wave-cut platforms, along with the strong exposure to winds from the east and south-west, may well have prevented the formation of woodland here at any stage. Indeed, commenting on its denuded appearance Ayala (1772) says these areas were covered in “monte”, that is matorral, in the 1600s. Much of the area may, therefore have been covered in a low matorral and open-ground steppe-like vegetation. We do not know. However, a sketch by Booth dated 1772 in the Gibraltar Museum clearly shows Windmill Hill (with a Windmill!) without a tree in sight with, significantly, a cow grazing in the foreground. Certainly much of the southern plateaux of Gibraltar presented this very open appearance after the 18th century through to today. The area south of Buena Vista Barracks was so barren and devoid of vegetation, as seen in some 18th century prints and 19th century photographs, that it was known as the Devil’s Bowling Green! The Europa Flats were, similarly, dominated by low vegetation. There were few buildings here but they included the Shrine of Our Lady of Europa and the Nuns’ Well, both of which were probably Muslim buildings. The Nuns’ Well is still in existence and continues to function as a reservoir of fresh water. The Shrine is gone and would have been situated approximately 50 metres east of the present shrine which is a mixture of modern architecture on a small 15th or 16th century Spanish Guardroom. The mosaic on the floor of the external patio is British and not, as often written, Islamic. The same confusion continues to today in the form of a British sentry post on the ridge of the Rock, between the Cable Car Station and O’Hara’s, which is still incorrectly attributed by many to the “Moors”. The entire area of Europa Flats must have been well used in Muslim times. The foreshore was called the Corral de Fez which led Portillo to speculate that people from that town had lived there in the past. The area of the Europa Flats was also fortified in the time of Abu Inan, son of Abu’l Hasan, and it is a part of Gibraltar which we have in mind excavating in the future.


In the 16th century there were vineyards on the Europa Flats which extended to the Caleta del Laudero (Little Bay), the Corral de Fez and the Shrine. By the middle of the 19th century there was no trace left of these and the place was described by Kelaart:

“…on the most southern point is a lighthouse, recently erected. This part of the rock contains but few shrubs, and upon the whole there are not here many species…Above the road is situated the governor’s cottage, a delightful summer residence.”


The foundation stone for the lighthouse was laid in 1838 by the governor Lieutenant General Sir Alexander Woodford. There was also a, reputedly Muslim, tower on the site of Deadman’s Hole by the lighthouse until quite recently.


Most of the prints and photographs of Gibraltar during the 19th century show the Upper Rock as a barren and highly inhospitable-looking place. The exceptions are Bruce’s and Ince’s Farm which, from an early date, stand out as dark patches of vegetation. They really were farms with well-defined boundaries at that time but they could not have been very large, judging from Kelaart’s remarks in 1856:

“On descending by a lower road from the signal-station, two or three small apologies for farms are passed…”


Presumably the vegetation throughout the Upper Rock was kept constantly down by grazing animals, especially goats, and it seems that the tallest vegetation was confined to the gardens. The Alameda Gardens had been opened to the public in April of 1816, thus replacing a large part of the remaining red sands (Chapter 4). Kelaart, with a particular interest in botany, described a number of the gardens in 1856:

“After he has passed the South-Port gate, he finds himself in the Alameda, which is tastefully laid out; and as he prolongs his walk, he is still more surprised to find that Gibraltar can boast of its gardens and walks lined with beautiful shrubs and plants, shaded by stately poplars and bella-sombras.”

“The road from Europa leads to a romantic little place, called Glenrocky, near Europa-pass, on which is situated the house now occupied by the chief justice; a pretty little garden is attached to it, and the ivy and aloe cover most part of the rock surrounding it.”

“…and just above the middle part of the town is the elegant residence of Dr Burrow, the archdeacon of Gibraltar, who has, with great taste and horticultural skill, laid out the garden surrounding the ‘palace’ with rare and beautiful trees…The stranger could scarcely picture to himself a good garden in Gibraltar; but there are several, even in the town, which may come under this designation. The extent of some of these would perhaps surprise him; among the principal ones are, the gardens attached to the quarters occupied by the colonels of artillery and engineers; the garden belonging to the celebrated wine-merchant, Mr. Glynn; the one just mentioned, belonging to the archdeacon; and, the largest of all, the convent garden.”


These gardens probably acted as reservoirs for some of the Mediterranean plants which would subsequently colonise the Rock but they also harboured an increasing number of exotics, some of which would take over areas at the expense of the native species.


The great naturalist William Willoughby Cole Verner who we met in Chapter 4 spent much of his time climbing the cliffs of the Rock and the sierras around us despite having sustained major injuries during the Boer War which forced him to retire from the Army and return to settle on the shores of his beloved Strait of Gibraltar. In his amusing and very direct style he describes the erection of an iron fence across the Upper Rock at the beginning of the 20th century:

“But all this happened long ago. When in a sudden access of hysteric caution following on years of ‘go as you please’ all the upper portion of the Rock was enclosed by a high spiked iron paling, some unimaginative official had the fatuity to style it officially ‘The Unclimbable Fence’, and numerous Orders were drafted with respect to it in which it was thus described. It is hard to imagine a more direct challenge to a man addicted to climbing. At this psychological moment I chanced to land at Gibraltar on leave from England. I climbed that fence, not for pleasure or for vanity, but as a matter of duty to the confraternity of birdsnesters. My ‘crime’ was never taken judicial notice of, and here I was happier than the luckless private soldier, who not long since committed the same offence and according to report was charged with ‘Neglecting to obey Fortress Orders, in that he, at Gibraltar, on April 1, 190-, contrary to the Fortress Order directing all persons to abstain from doing so – climbed the Unclimbable Fence!”


It seems that military considerations therefore restricted access to the Upper Rock at the beginning of this century. The remnants of this rusty-coloured fence can still be seen in parts of the Upper Rock, having run from Jews’ Gate in the south to the Willis’s Battery area in the north. The fence would appear to be responsible for the growth of the vegetation on the Upper Rock. We cannot properly call it regeneration because it is unlikely that, after anything between as little as two and as much as six hundred years of human action, the landscape could in anyway return exactly to what it was like before. Apart from anything else there were the introduced exotics, by then not just from America but also Aloes from Africa, Gum Trees (Eucalypts) from Australia and so on, to contend with. It seems that the fence may well have stopped altogether the access to the Upper Rock of the goatherds and their animals and that these would have been confined then to the lower slopes on the western side and the sand slopes and cliffs on the eastern side.


It is certainly true that, by and large, the vegetation on the Upper Rock developed early in the 20th century, a process which has not yet reached its climax in some areas. Photographs taken at different periods this century show very clearly the process of colonisation by shrubs and then trees.  The aerial photograph of 1953 shows a well-established matorral in many places but the lower slopes, below the fence, where goats were still grazed remain barren. The last goats must have disappeared shortly after. There certainly were none by the 1960s. Even today these lower slopes, now with a considerable growth of shrubs and trees, are clearly behind the rest of the Upper Rock which has a taller and denser matorral. A similar situation has occurred at the now abandoned watercatchment below Rock Gun which is gradually developing a growth of shrubs but which still stands out as a visible scar in the Upper Rock landscape. Even within the time that we have been studying the Rock we have been able to record the changing patterns. Many areas of the Rock which we had surveyed in the 1970s and which we re-examined in the mid-1990s had become denser and taller. Some of the shrubs which were typical of open matorral, especially some of the brooms, had been replaced in many places by shrubs of the deep shade understorey of woodland. Many olives in particular had developed from tall shrubs to mature trees. These changes were also reflected by changes in the fauna. We had been studying two species of insectivorous birds, closely-related warblers, which breed on the Rock. The Sardinian Warbler was the commoner of the two in many areas in the 1970s, being a species typical of a range of scrub vegetation. The Blackcap was more a bird of the mature scrub and woodland and we had discovered in the 1970s that it had altered its wing shape and general anatomy to survive in the conditions at Gibraltar. The development of the vegetation had favoured this species at the expense of the other in the intervening twenty years. Something similar must have occurred at the turn of the century. The ornithologist Howard Irby recorded how, in the 1860s onwards two warblers bred on the Rock. These were the Sardinian Warbler and the Dartford Warbler, the latter being a species of very low bushes. The Blackcaps were then restricted to the few tall trees in the gardens. Already by the 1970s the Dartford Warbler no longer bred on the Rock as its preferred habitat had gone and its appearance on the Rock was confined to the migratory periods and then it would most frequently be seen in the more open vegetation such as at Windmill Hill or the North Front Cemetery.


In our opinion it is the birds, species such as the Blackcap, which have contributed to the rapid development of the vegetation of the Upper Rock in under a century. By far the most abundant shrubs on the Upper Rock are fruit producers, species which have an annual crop of small fruit. Most species fruit in the autumn and the winter a notable exception being the spineless Buckthorn which fruits in the summer months. The Lentisc, the Osyris, the Spiny Asparagus, the wild Olive, among others, all fruit at this time and each has its own time slot which is different from the next. It is all part of a strategy which Mediterranean shrubs have evolved. Think of it as parental investment. The plant produced offspring in the form of seeds and it is in the plant’s interest that these seeds should fall well away from the parent plant so that it has good access to light. The fruit which surrounds each seed is an energetic burden for the plant but it has to assume it as a load. The fruity pulp is rich in nutrient and high in water content (the composition varies from species to species) and is attractive to birds especially at a time of the year when insects are becoming scarce. The autumn and the winter see many migrants crossing the Mediterranean into Africa or arriving here to spend the winter. So the plants have a captive market! The birds swallow the entire fruit and the unwanted seed, the plant’s offspring, is ejected in the faeces, usually far away from the parent plant. In some species the relationship has evolved to such a degree that the seed will not germinate effectively unless it has travelled through the gut of a bird! Is it, therefore, surprising that the majority of the new colonisers of the Upper Rock are plants that have their seeds dispersed by birds? Their spread has been much more rapid than that of other species which were here on the Rock originally and which do not rely on bird dispersal. Thus there are still very few Carob Trees on the Rock. They lost ground and never recovered it. Thus the vegetation of the Upper Rock, unique and very beautiful, with an apparent air of naturality is a combination of species that were never fully removed by human action (such as the Dwarf Fan Palms or palmettoes), others that were here all along and which recovered after the removal of goats (such as the wild Olives and the Lentiscs), others which were once much commoner and which have not succeeded in recolonising (such as the Carob), others which did not grow on the Upper Rock but which are native to the area and which were planted to provide shade when no other trees grew on the Rock (such as the Stone Pines) and yet others which humans have brought even from other continents (such as the Eucalypts or the Aloes).