The following is an extract from the 1999 book ‘Gibraltar at the end of the Millennium: A Portrait of a Changing Land’ by Clive and Geraldine Finlayson:
One of the earliest named British batteries in Gibraltar was Forbes’ Battery at the extreme northern end of the Northern Defences, overlooking the north-western corner of the isthmus. It was named early in the 18th century after Lord Forbes, third Earl of Granard, who had been aide-de-camp to the Prince George Hesse of Darmstadt when he landed on Gibraltar in 1704. He was later to briefly participate in the defence of Gibraltar during the 1727 siege but before that he had arrived on the Rock in 1726 when he designed and, with his men, constructed the battery which was to carry his name. The interesting feature of this two-cannon battery was that the guns pointed towards the Grand Battery and not to the isthmus. In other words, should the enemy penetrate that far they would be fired upon from behind. After the 1727 siege the Spaniards admitted that this battery had been the one they had feared most. A barrier which was placed to control the entrance to the garrison between the base of the Rock, below Forbes’ Battery, and the marshy ground and coast to the west was naturally given the name Forbes’ Barrier. During the early and middle of the 19th century significant quarrying took place in this area as described by Edward Kelaart, botanist and medical officer of the garrison, who arrived in Gibraltar in 1843 and published his Botany & Topography of Gibraltar in 1856:
“Passing along the moat, after leaving the bay-side guard, a road to the right leads to Catalan-bay, almost round the northern side of the rock, which has lately been extensively quarried for stones to erect the new works...”
A significant amount of scarping had been undertaken in this area by the British in the early 18th century to prevent infiltration by Spanish troops. A case in point was a cavern below Willis’s Battery, sealed after an attempt by Spaniards to mine it in 1727. This sealed cavern can be seen today from Forbes’ Quarry but it is totally inaccessible, the slope leading to it having been removed in the 18th century. The Reverend John White arrived in Gibraltar as military chaplain in 1756 and remained on the Rock for 16 years. He described this part of Gibraltar like this:
“The whole north face of the rock is, as it were, a perpendicular wall. Immediately under Willis’s Battery a vast sloping bank lies against the foot of the rock to the height of about two hundred feet. This bank consists of sand, earth and fragments that have fallen from the main rock for ages past. It is clothed with verdure in many parts, and may be easily climbed to the top where it terminates against the rock, which rises above it perpendicular about two hundred feet more. About half-way up this slope was formerly a cavern or cleft running a considerable distance under the rock whereon Willis’s Battery stands. In this cavern the Spaniards in the last siege lodged a vast quantity of gunpowder, making use of it as a magazine. They were said to have some intention of blowing up the incumbent rock by mining still further under it; but this scheme was never put into execution. The cavern has since been walled up on the outside with solid masonry.”
Image: North view of Gibraltar. 2 January 1775. Engraving. W.H.C. Jones (sculpt.), J. Mace (artist). J. Boydell, publisher. Cheapside, London.