The Old Mole was built in about 1618 and joined the City Wall, with access being through the Waterport Gates over a small bridge. This mole was extended with a battery of guns in 1727 to help protect the land approaches to the City.
The battery was later extended to form the Devil’s Tongue Battery or the Old Mole Battery. This battery constructed by the British between 1779 and 1783 and proved highly effective during the Great Siege. In 1848, John Fox Burgoyne, the Inspector-General of Fortifications (IGF), made a recommendation that the guns on the Devil’s Tongue Battery be directed into Gibraltar Harbour in order to protect the shipping. The black and white image from about 1879 shows the Devil’s Tongue with some guns facing north to cover the land approach, and others facing South to cover the harbour. The Mole Head Battery was added to the end of the Devil’s Tongue (Old Mole) at some time in the latter half of the 19th Century.
In 1895 the Old Mole Head was absorbed into the new Gibraltar Harbour and the whole structure is now landlocked. The Devil’s Tongue Battery is used as a garden nursery.
Brickwork on the Old Mole indicates two distinct periods of building. The earliest stage is close to the City Walls with the extensive use of red brick. The area closer to the Old Mole Head, built later, is constructed from large white blocks of granite stone. The whole length of the battery was mounted with guns, some facing North and some facing South.
In 1859 returns the Old Mole was reported as mounting :
- Eight 8-ins guns
- Nine 32-lbs
- One 32-pdr Carronade
- Six 13-inch (Mortars?)
By 1886 there had been a general upgrading of the guns to:
- Six 13-ins LS Mortars (Presumably the same ones as in the previous return)
- Six 8-ins Smooth Bore 65-cwt on Garrison Standing Carriages
- Six 64/32-pdr Rifle Muzzle Loaders on Garrison Standing Carriages
- One 8-ins Howitzer.
We do not know exactly which guns were position on the Mole and which on the mole head. It would appear that there is at least two gun embrasures facing out to the West on the Mole Head.