The Great Siege Tunnels of Gibraltar, also known as the Upper Galleries, are a fascinating part of Gibraltar’s history. They are a series of tunnels carved inside the northern end of the Rock of Gibraltar, dug out from solid limestone by the British during the Great Siege of Gibraltar in the late 18th century.

Here’s a brief overview of their history and significance:

Historical Background: The Great Siege of Gibraltar was an intense conflict that took place from July 1779 to February 1783 during the American Revolutionary War. It was an attempt by France and Spain to capture Gibraltar from Great Britain.

Construction: The tunnels were constructed to address a blind angle on the northeast side of the Rock, which could not be covered by existing gun batteries. The idea was to mount a gun on a spur of rock known as The Notch. Since there was no path due to the vertical cliff face, it was suggested to dig a tunnel to reach this point.

Design: The work was done mainly by hand, using sledgehammers, crowbars, and gunpowder blasts. The initial tunnel took thirteen men five weeks to dig a length of 82 feet (25 meters). To improve ventilation and reduce the fumes from blasting, a horizontal shaft was also created.

Today, the Great Siege Tunnels are partially open to the public and are controlled by the Gibraltar Tourist Board. They offer a glimpse into the military ingenuity of the past and are a popular attraction for visitors interested in history and military engineering.