A promontory of rock, in the S. of Spain, about 2 m. square and over 1400 ft. in height, connected with the mainland by a spit of sand, forming a strong fortress, with a town of the name at the foot of it on the W. side, and with the Strait of Gibraltar on the S., which at its narrowest is 15 m. broad; the rock above the town is a network of batteries, mounted with heavy cannon, and the town itself is a trade entrepot for N. Africa; the rock has been held as a stronghold by the British since 1704.