I think it sounds like you mean The Rock of Gibraltar. ( Rock_of_Gibraltar_northwest.jpg ) This is at the western end of the Mediterranean Sea, on the north side. It was seized from Spain during the War of Spanish Succession (about 300 years ago) and has since been governed by Great Britain, but recently granted self government by the British. The people there are descended from Spanish and British, but have many times rejected Spanish efforts to control the territory, most recently in 2006.
Most of the territory is dominated by the huge Rock, which has, over the years been honeycombed with tunnels and gun ports. The territory still remains a large and important part of British defence policy, as it controls the entrance to the Mediterranean