The Great Siege Tunnels

During the Great Siege of 1779-83, Gibraltar's defenders answered an engineering riddle - how to mount guns on an unclimbable north face - by digging: soldiers carved galleries through the limestone by hand and gunpowder, opening embrasures that still stare over the isthmus and bay from inside the Rock itself. The tunnels' cool passages walk visitors past cannon at their ports, tableaux of the digging teams, and windows in the cliff face with the views that justified the labour. The system's later extensions honeycombed the Rock further, making 'solid as the Rock' geologically ironic ever since.

History

The Great Siege, France and Spain's attempt to take Gibraltar during the American Revolutionary War, lasted from July 1779 to February 1783, the fourteenth and last siege of the Rock. To cover a blind angle on the north-east side, Sergeant-Major Henry Ince proposed tunnelling to a spur called the Notch, and work began on 25 May 1782, by hand with sledgehammers and crowbars and with gunpowder; at first it took thirteen men five weeks to dig 82 feet, until a ventilation shaft blasted through the face suggested mounting guns in such openings. By the end of 1783 about 908 feet of tunnel had been cut, with the Windsor Gallery, King's and Queen's Lines, St George's Hall and Cornwallis Chamber, their embrasures once hung with rope mantlets against enemy fire (Wikipedia, Great Siege Tunnels).

What's there

• The hand-carved galleries - 18th-century digging at cannon scale.
• The embrasure windows - gunports in the sheer north face.
• The cannon stations - guns at their original ports.
• The bay panoramas - the views the labour purchased.

When to go

Year round - the tunnels keep their cool; pair with the upper reserve's macaques and viewpoints in one Rock day. Mornings beat the tour-group waves.

Good to know

Passages involve slopes and steps in numbers - comfortable shoes and moderate fitness suffice; claustrophobia rarely troubles the generous galleries. The combined-ticket structure rewards planning the whole Upper Rock day.

Nearby

The macaques' dens, St Michael's Cave and the cable-car summit.

Key facts