16. Fort Wadsworth
Fort Wadsworth is located in the shadow of the Verrazano-Narrows Bridge, in Staten Island. Its military roots date to the 1660s and prior to closing in 1994, it was possibly the longest continually-manned military installation in the country. Its most prominent feature is Battery Weed, which was completed in 1861. When it was decommissioned, it was transferred to the Park Service and is now open to the public.