Castle Clinton
Castle Clinton is a circular sandstone fort in Battery Park at the southern tip of Manhattan, New York City. It was built to defend New York City from English forces during the War of 1812, but never saw action in that or any war.
The US Army stopped using the fort in 1821 and New York City took ownership in 1822. It served as a restaurant, opera house, and theatre until 1854, and then as an immigrant landing depot until 1890. It then became the site of the New York City Aquarium until 1941. It was desigated a National Monument in 1946. Today it appears much as it did in its early days, and contains a museum.