Gibraltar Museum



Round Towers, Walls, Bastions and Inside the Rock


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.


It had been some years earlier that we had been reviewing the collection of prints and watercolours in the Gibraltar Museum as part of our project of documenting the collections. Among the many pieces we had a print of 16th century ships near a fortified port. The description of the print did not help and we could not tell what it was depicting. There was nothing to suggest to us that it was Gibraltar. After the excavation of the Gate of La Barcina (Chapter 4) we decided to re-examine the various plans and images of Gibraltar in the hope that we might find additional clues to help us in understanding the landscape better. The process was two-way: the prints helped us understand the excavations but the excavations also helped us interpret the depicted scenes. A set of two prints which have been on display in the Gibraltar Museum for many years depict the destruction of the town after the Great Siege. The town was largely destroyed by the constant pounding of cannon and there was little to help us interpret the location of the scenes. Later on we realised that one of the battered buildings was the Spanish Church (Cathedral of St. Mary the Crowned – Chapter 7). The other view showed a street in ruins and, at the end of the street a crumbling tower with a large Union Jack flying. A Spanish 18th century plan of Gibraltar at the time of the Siege curiously marked a tower in the area of the junction of Casemates to Main Street with the caption “where the English fly their flag”. After detailed consultation of several maps and plans we came to the conclusion that it was the medieval tower that protected the Gate of La Barcina (Chapter 3) which was depicted and that it still stood during the Great Siege, the British using it as an elevated position from which to fly the flag. So we achieved several things. We were able to identify the print as a view of the northern end of Main Street where it joined the Casemates Square and we also understood that the base of the medieval tower that we had excavated had not been completely destroyed until the Great Siege!


That brought us back to the 16th century print that we had examined years earlier. In the foreground was a tall, round, tower with small, s-shaped, projections, known in Spanish as matacán and whose function was in supporting structures that would permit archers to defend positions vertically below which would otherwise not be in the line of fire. It was at that point that everything became so clear. Without speaking we excitedly got one of our cameras, left the museum and rushed across the street down Line Wall! We went into the large garage on Line Wall, between the British and American War Memorials known as Capurro’s Garage. Under the first floor, and surrounded by cars, were the remains of an old tower which had been known for a long time. There, staring right at us, was part of a round tower with the same matacanes as the tower in the print!


We searched the archive further. The photographs of the Devil’s Tower (Chapter 4) opened up another window. The Devil’s Tower, demolished during the Second World War was also round and had the same kind of matacanes! Shortly afterwards we became aware of the existence of the 1567 sketches of Anton van den Wyngaerde and we acquired copies. There was the Devil’s Tower and the entire front of the line wall, facing the Bay of Gibraltar, was lined with round towers! The 16th century print was of Gibraltar and the remains of the round tower in Capurro's garage the last of the round towers of Gibraltar. When were these towers built and by who and when were they demolished?


They were in their full splendour in 1567 so they must have been erected before that date. Since the Spaniards had captured Gibraltar in 1462 we deduced that the towers could be part of the Spanish works in those one hundred years or they could have been earlier medieval constructions by the Merinids when they walled the city in the 14th century. There is very little to go by in order to solve this problem although our hunch is that they may well be Muslim.


Certainly Ibn-Marzuq’s description of the Merinid constructions in Gibraltar would seem to support this view:

“In that way he (Abu'l Hasan) surrounded it (the city) completely, as well as other parts now well walled and which have passageways and towers. He also placed round towers and houses along the whole length of the coast.”


Their demolition is equally enigmatic but here we may have some clues. On the 25th April 1607, the Dutch Fleet led by Admiral van Heemskirk aboard the Aeolus entered the Bay of Gibraltar and attacked a squadron of ten large Spanish galleons and eleven smaller ships which were anchored under the protection of the guns of Gibraltar. In the ensuing fight Heemskirk and the Spanish admiral Juan Alvarez D’Avila were killed but the smaller and more manoeuvrable Dutch ships won the day. The entire Spanish fleet was sunk and 3,000 seamen were killed while the Dutch lost no ships and only 100 men. The Dutch still celebrate their famous victory – the Battle of Gibraltar. It was in April of 1999 that Prof Clive Finlayson was attending a meeting of European Maritime Museums in Amsterdam. The meeting was in the splendid National Maritime Museum where a famous oil painting depicting the Battle of Gibraltar hangs with pride. The huge painting was in a room dedicated to the event and when he saw it, it was not the battle that caught his eye but the Rock in the background with the sea lapping the line wall and a group of Spanish soldiers helplessly looking on from the top of a round tower! Another clue: Bravo’s account of the fortifications (1627) specifies the recent changes that had been made to the defences of Gibraltar. His plans no longer show round towers. They had been replaced by platforms which could take heavy artillery. So the towers were replaced by platforms some time between 1567 and 1627. The Battle of Gibraltar took place in the middle of this period. Could the Spanish military planners have realised that the battle might not have been lost had their coastal artillery been able to support the stranded fleet? Perhaps it was the Battle of Gibraltar that determined the fate of the round towers!


There is a wonderful section view by James in the History of the Herculean Straits of the defensive walls where the old fountain was situated near the Piazza (Chapter 7). It shows the sea wall before the 19th century modifications and additions. It does not descend vertically to the sea but at an oblique angle. We are looking at the Spanish wall, repaired as necessary by British Engineers. Capurro’s garage is on the line wall and for over one hundred metres on either side of the round tower a wall, now covered in white paint, runs lengthwise and it is at an oblique angle! Here we have the remnants of the Spanish defensive wall. James’ section also shows a rampart to the east of this wall and the old Moorish wall even further east.


Line Wall Road runs along the length of the rampart. It is an unnaturally elevated ground, an infill.  The drop on the east side of the road, evident in a number of access points into the town, must represent the position of the original defensive sea wall built in the days of Abu-l Hasan and extended in the reign of his son Abu Inan (1350-58) south to Europa Point. It would run from Casemates (the Gate of the Atarazana) along the east side of Line Wall road southwards towards the area of the 16th century South Bastion and the Spaniards had not constructed on or repaired this wall. Instead they built a new one further out.  The pattern was repeated in the 19th century when the British built a new line wall, much of which is visible along the eastern side of Queensway, west of the Spanish wall. The pattern is obscured in some places where the geography or the good condition of the Moorish Wall dictated. Thus when we excavated the old Lovers’ Lane in search of the medieval walls we found that the Moorish and the Spanish wall followed the same line and the remains were a metre underground running down the middle of the street with the later 19th century Wellington Front additions to the west.  To the east is the Convent itself, the remains of the original Franciscan monastery of circa 1490 still visible in the old stables. Near the outer eastern perimeter wall of the Convent we found an old ossary, probably belonging to the old convent. The perimeter walls were beautifully illustrated in some 18th century Spanish plans to capture Gibraltar.


So the western coastline of Gibraltar, which began to be transformed when the Merinids built the atarazana (Chapter 3) must have followed a line from the eastern side of Winston Churchill Avenue, south towards the North Bastion which must have been a rocky promontory, then in and south along the centre of Grand Casemates Square and from there south along the eastern side of Line Wall Road to approximately the area of the South Bastion which must have been another rocky promontory. From there the coast would have followed the line traced by the 19th century walls, that is at the eastern extreme of the Dockyard, to the area of Rosia south of which the coast is probably, save minor recent reclamations, close to the original.


During the 16th century Gibraltar was constantly being attacked and sacked by pirates so that a southern defence had to be constructed for the first time. We stress first because there are many historical accounts, even quite recent ones, that describe a “Moorish” wall running up the Rock north to the old Signal Station (the Hacho in Spanish times, now Cable Car Upper Station) of Charles V Wall to a small defensive tower known as Nuestra Señora de Guadalupe. This is wrong and this wall is actually the wall constructed and not completed by the engineer Frattino in 1575 in the reign of Philip II and it is not, obviously, included in Wyngaerde’s sketches drawn eight years earlier! Portillo makes it clear that Gibraltar had not previously had a southern flank defensive wall. The wall which runs up the Rock towards the point known as Mount Misery (La Quebrada on Spanish maps) and which is called the Philip II Wall is, in fact, a continuation of the Charles V Wall constructed by the engineer Calvi in 1552 and which started near the sea in the South Bastion (the Baluarte de Nuestra Señora del Rosario). The construction of this wall, in our opinion, significantly contributed to the removal of much of the native vegetation which grew along the central parts of the Upper Rock (see Chapter 6). The intention had been to fully enclose, for the first time, the castle with outer walls according to Portillo, the northern flank having been covered by a wall above the castle which was constructed in the time of Don Álvaro de Bazán (father of the first marquis of Santa Cruz) in 1538 and which reached a tower (in the area of Willis’s) built by King Alfonso XI when he laid siege to Gibraltar in the 14th century. These walls and tower were in poor condition in the 17th century. During our excavations in Casemates (Chapter 3) we found several large stone projectiles which we have attributed to Alfonso XI’s attempts to regain Gibraltar in 1333 during which he used catapults. These projectiles were aimed at the castle and the Muslim galleys in the atarazana below and the catapults had been set up on the ground above the castle.  There are also a few of these projectiles within the castle precinct today!


Portillo tells us that south of this wall in the area of Southport Gates there was a moat that had a pond that was full of frogs. Bravo’s plan shows the moat running down to the sea in the position of Ragged Staff Gates today. The moat was opened by Calvi. The old Muslim Gate of Algeciras (which like that of Granada had a key sculptured on it) was replaced by the Gate of Africa by Frattino who commenced the Bastion of Nuestra Señora del Rosario (on the South Bastion). Some tidal water may have been allowed to enter the lower reaches but stagnant rainwater and freshwater from the nearby aqueduct must have contributed along the higher portions if frogs were to survive there.  Indeed there was a freshwater well there called La Tarasca. The remnants of the moat appear in many 19th and 20th century photographs of the area and it was not until the mid-1960s that the rest, which had remained as a sunken garden, was filled in to add the road and the Referendum Gates.


We can therefore, based on our present knowledge trace the evolution of the defensive walls of the city of Gibraltar as follows. In the late 12th century Al-Mumin constructs the City of Gibraltar. There was probably a tower where the present Tower of Homage is and a defensive wall around a small town on the skirts of the castle. It is in Abu-l Hasan’s and his son and successor Abu Inan’s time in the 14th century that the fortifications develop. The tower of the castle is built in its present form and a gatehouse is positioned along the southern flank wall. The precinct of the Qasbah is walled (or the walls strengthened) and the small town (the Spanish Villa Vieja) is protected and separated from the lower area where the atarazanas are constructed. It is in order to afford added protection to the ships within the atarazana that an outer sea wall is erected in the position of the present Water Gate, thus enclosing the beach and intertidal area. This intertidal area must have had to be regularly dredged and eventually silted up in Spanish times when houses were built on this land (Chapter 3). The sea wall was extended along the eastern end of Line Wall Road as described above and eventually reached all the way to Europa Point. The Spaniards strengthened the walls further in the late 15th and early 16th centuries.


Changes in methods of defence and the need to provide artillery positions and emplacements along the line wall caused the removal of the medieval round towers early in the 17th centuries and their replacement by bastions and platforms. During the 16th century a defensive wall is erected for the first time from the South Bastion to the top of the Rock and a moat is dug on its southern side near the base while much vegetation is removed higher up the slopes (Chapter 6). The British repaired the damaged walls in the 18th century and commenced a programme of cliff scarping and removed the remaining vegetation (Chapter 6). The entrance to Gibraltar into the Villa Vieja via the Gate of Granada, which Portillo relates had a Muslim key sculptured on it signifying the importance of Gibraltar, was severed by scarping the cliffs in the Forbes’ area leaving just the single land entrance to Gibraltar via Landport. It is late in the 18th century that the defences were enhanced through tunnelling and the creation of the Galleries. John White tells us that:

“This place is since secured effectually from surprise, and the remainder of the rock, till you come round Europa Point, is a lofty hanging cliff, washed by very deep water and needing no other defence than that what Nature had given it. From Europa Point to the New Mole are constructed many walls and batteries wherever a landing might possibly be attempted. And from the New Mole to the Old Mole, being the whole Western side of the garrison, the place is defended by a line wall and parapet, flank’d with numerous batteries.”


During the 19th century the British reshaped the line wall and extended it westwards. The end of the 19th century saw the further extension outside these walls as the dockyards were built and this marked a period of great upheaval and destruction as quarries were opened in many parts of the Rock. For a long time Gibraltar’s lack of a sheltered harbour had reduced its importance as a naval base and it had been considered to be no more than an observation and staging post, subordinate to Minorca or Malta. For the greater part of the 18th and 19th centuries the Royal Navy depended on the limited facilities afforded by the Old Mole (which had to be shared with commercial shipping) and later the extended New Mole, where incidentally a pentagonal tower known as the Torre del Tuerto stood until it was destroyed in the 1704 landings. The tower was attributed to the Merinids, which would be in keeping with our view on the date of construction of the coastal towers, Abd’l Malik who captured Gibraltar being the one-eyed (tuerto in Spanish) son of Abu’l Hasan. The New Mole dated to Philip III of Spain’s visit to Gibraltar in 1618 when he ordered the renewal of the Torre del Tuerto, the enlargement of the Old Mole and the start of the New Mole. Work commenced the following year and it was finally completed in 1658.


For a long time supplies were stored in the White Convent until the Victualling Yard was constructed near Rosia Bay in the first years of the 19th century and was completed in 1812 along with the pier at Rosia. The New Mole was extended in 1851 by 1,309 feet. It was not until the last years of the 19th century, however, that the dockyard of Gibraltar was to be extended with massive environmental consequences. It was in 1893 that a contract was awarded to Messrs. Topham, Jones and Railton for the further extension of the mole by 1,000 feet. In fact, the length was changed to a further 300 feet later by an addition to the original contract. The following year the Admiralty began work on the project for the enclosure and defence of the harbour and the extension of the dockyard.  According to Adam Scott who was one of the engineers involved in the works, the principal works embraced by the project were:

Sect.  No.  1 – A southern breakwater extension, having a total length of 2,700 feet, including the 1,000 feet begun in 1893.

Sect.  No.  2 – A detached breakwater 2,720 feet in length, situated between the north and south breakwaters and lying more or less N.N.W.  (True).

Sect.  No.  3 – A large northern mole, with coaling-jetties, and viaduct.

Sect.  No.  4 – An extended naval yard, including three large graving-docks, wharf-walls, slipways for destroyers, pumping-engine house, workshops, storehouses, offices, railways, etc.

Sect.  No.  5 – The dredging of the harbour.


The materials used came from diverse sources. Portland cement was used throughout the works and the quantity which had been delivered by the 23rd December 1905, was 207,463 tons! Adam Scott describes the sources of raw materials:

“The rubble and dressed limestone for the extension of the southern mole were obtained chiefly from the Europa quarries (i.e.  Camp Bay); the rubble for the detached breakwater and the northern mole from the Catalan Bay and the North Front quarries. The roughly dressed limestone required for the dockyard buildings, etc., was procured from the Catalan Bay and the Monkey’s quarries. The bulk of the limestone ahslar, for quay-walls, docks, and buildings, was obtained ready dressed from Spain, being brought down by railway to Algeciras, and transported in lighters across the Bay to the works. Most of the granite was from Cornwall, some from Norway, and a little from Italy. Sand was obtained from the slopes on the east side of the Rock.”


It was shortly after that the watercatchments covered the remaining sands (Chapter 4). The quarrying which took place on the east side transformed its character for ever and, worse still, made the area easily accessible.  It is hardly surprising that this increased accessibility, along with the disturbance of the two World Wars caused the extinction of many species which had lived on the Rock since the days of the Neanderthals, for example the Bonelli’s Eagle, the Egyptian Vulture and the Osprey. Adam Scott describes how the area was made accessible:

“A shipping-jetty was constructed at bayside, and the block-yard was established on the North Front, at the Devil’s Tower, by the eastern beach. Railway communication (metre-gauge) was established between the dockyard and the commercial mole through the Rock and round by Catalan Bay, North Front, Bayside, and Waterport. Ultimately the railway was continued south from Waterport along the foreshore, outside the line wall, and connected with the dockyard, thus completing the circle. Until the works were begun locomotives were unknown at Gibraltar.”


The reclaiming of land from the sea, which had started when the western area of La Barcina was gained in the 16th century (Chapter 4) reached an all-time high only to be matched in the late 1980s when the large areas west of the viaduct (which was then lost) were reclaimed using sand obtained from the sea-bed on the south-eastern side of the Rock.


The 20th century therefore started another major episode in environmental transformation, on a far greater scale than anything that preceded it. It was not limited to the outside of the Rock. The early modifications inside the Rock would have been relatively minor. We saw how St. Michael’s Cave was used for shelter in Spanish times (Chapter 6) and it was regularly visited from the 18th century as a curiosity, leading to a degree of deterioration. Kelaart (1856) describes one such event:

“Caves of various size exist in this formation. The largest, called St. Michael’s Cave, is situated about the middle of the rock, and nearly eleven hundred feet above the level of the sea; perhaps there are a few caves in similar formations equal to this in picturesque effect, though there are many of larger dimensions. The interior is shown to the public when the rock is visited by some distinguished personage, or a particular friend of the Colonels of Artillery or Engineers; it is then seen to the best advantage: a host of people is assembled near the entrance of the cave at the hour appointed. Martial music sounds. The gates are opened, and the cavern is entered with the utmost degree of caution, the ladies of course assisted by the gentlemen, the descent being very slippery from the accumulated moisture.  Wax tapers burning at distant intervals, cast a dim light over all around…”


Subsequent large-scale transformations and visitor pressure have rendered the cave effectively dead. The practice of the removal of stalactites and stalagmites from caves also appears to have a long tradition, judging again from Kelaart’s remarks:

“The stalagmitic formations bear a good polish, and are known by the name of “Gibraltar Rock”, and consequently are erroneously supposed to constitute the prevailing rock of Gibraltar. Of this rock are manufactured small cannons, pliiars, etc., for the mantel-piece, as also personal ornaments.”


Other caves around Gibraltar have also suffered from decades of human pressure, from the elimination of bat colonies (e.g. in Martin’s Cave), through large scale dumping of refuse (e.g. Judge’s and Poca Roca Caves), transformation for military purposes (e.g. Mediterranean and Monkey’s Caves), uncontrolled excavation of archaeological deposits by amateurs (e.g. Mammoth, Sewell’s, Goat’s Hair Twin, Poca Roca, Collins’ to name a few) to total annihilation (e.g. Genista I and Forbes’ Caves). New tunnelling works have opened up new cave systems which had rested peacefully for millennia. The most precious of these are Crystal and New St. Michael’s Caves which are today in high risk of going the same way as some of these other caves if protection is not afforded to them soon. 


The discovery of New St. Michael’s Cave was the result of tunnelling during the Second World War.  We saw in Chapter 4 how the tunnelling spoil from AROW Street created an artificial beach on the eastern side of the Rock. The scars of tunnelling are still visible in many parts of the Rock.  Above Gorham’s Cave or just north of the Calahorra (and below the Middle Galleries) there are huge piles of debris which in some cases prevent growth of vegetation and in others may even be hiding important archaeological sites. The area just north of the Calahorra, for example, was the site of Gibraltar’s fifth and least known medieval district. Apart from the Qasbah, the Villa Vieja, La Barcina and La Turba early accounts talk of the Albacar. This medieval name referred to a walled area outside the castle or city precinct. Cattle and other animals were put in this enclosed area at night or in case of alarm. From available descriptions it appears most likely that the Albacar was situated in an area roughly from the present location of Hay’s Level down towards the site of Hesse’s Demi-Bastion and much of the upper part of this is covered with tunnelling spoil making the prospect of excavation there a nightmare.  Perhaps one day we might find the remains of the Albacar…