Ft. Wadsworth:

Sitting on a hill high above the Verrazano Bridge, Ft. Wadsworth stood as a citadel protecting New York harbor for over 200 hundred years. Originally constructed by the Dutch in 1636, the site has breathtaking views of New York Harbor that can only be seen from its ramparts. Its massive gun emplacements deterred the British from attacking New York City during the War of 1812 and the Confederates from attacking during the Civil War. When the fort closed in 1994, it was the longest active military base in the United States. Today is managed by the National Parks Service and is open to the public as part of the Gateway National Recreation Area.