Castle Clinton National Monument
Located in Battery Park, the Castle Clinton National Monument was constructed as a fort to guard New York Harbor just before the War of 1812 . Over the course of 200 years, Castle Clinton has gone through several transformations. Once new defenses were built further out in the harbor, the fort was turned over to the City of New York. In 1824, Castle Clinton became an entertainment complex, in 1855, an immigration reception station, and, in 1896, an aquarium. The National Park Service assumed control of the old fort in 1946, restoring it to its original design as a fortification.
Free tours from Park Rangers are available throughout the day. Groups of 10 or more should call to reserve a tour.