Great Siege Tunnels

The Great Siege Tunnels in the British Overseas Territory of Gibraltar, otherwise called the Upper Galleries, are a progression of passages inside the northern end of the Rock of Gibraltar. They were uncovered from the strong limestone by the British amid the Great Siege of Gibraltar toward the finish of the eighteenth century. The Great Siege was an endeavor by France and Spain to catch Gibraltar from Great Britain amid the American Revolutionary War. It was the fourteenth and last attack of Gibraltar, which kept going from July 1779 to February 1783.
Amid the attack, British and Spanish powers confronted each different over a roughly 1 kilometer 0.62 mi wide stretch of the muddy open ground that structures the isthmus promptly toward the north of the Rock of Gibraltar. The British lines blocked access to the City and the western side of the Rock, while eastern side of the Rock was difficult to reach on account of its lofty terrain. Guns were put in a progression of batteries on the north face of The Rock, giving covering fields of discharge with the goal that infantry assaults would go under overwhelming shoot all through their advance.

The catalyst for the development of the passages originated from the army's have to cover a visually impaired point on the north-east side of The Rock. The main arrangement found to cover that edge was through a firearm mounted on a goad of shake known as The Notch. There was no plausibility of building a way there because of the vertical precipice confront, so Sergeant-Major Henry Ince of the Military Artificers recommended burrowing a passage to achieve it. His arrangement was affirmed and development work started on 25 May 1782.