National Historic Site (United States)

A National Historic Site (NHS) is a protected area of national historic significance in the United States. An NHS usually contains a single historical feature directly associated with its subject. A related but separate designation, the National Historical Park (NHP), is an area that generally extends beyond single properties or buildings, and its resources include a mix of historic and sometimes significant natural features.

As of 2015, there are 50 NHPs and 90 NHSs. Most NHPs and NHSs are managed by the National Park Service (NPS). Some federally designated sites are privately owned, but are authorized to request assistance from the NPS as affiliated areas. One property, Grey Towers National Historic Site, is managed by the U.S. Forest Service.

As of October 15, 1966, all historic areas, including NHPs and NHSs, in the NPS are automatically listed on the National Register of Historic Places (NRHP). There are also about 80,000 NRHP sites, the large majority of which are neither owned nor managed by the NPS. Of these, about 2,500 have been designated at the highest status as National Historic Landmark (NHL) sites.