Castle Clinton National Monument

Castle Clinton began its life as the Southwest Battery, a stout sandstone fortification built on a small, artificial island just off the shore of Manhattan. It was constructed between 1808 and 1811 to protect New York Harbor from a potential British invasion during the War of 1812. Although it was armed with twenty-eight heavy cannons, the fort never actually fired a single shot in combat, as the presence of such defenses helped deter enemy fleets from entering the harbor.