Historic Landmarks and Historic Districts Historic landmarks and districts are granted official recognition and protection for their contribution to the cultural and aesthetic heritage of the nation's capital. Most historic properties are buildings or districts, but they may also be archaeological sites, engineering structures, sculpture, or landscape features. A property designated as historic for the purposes of DC law may also be recognized as historic by the Federal government. Historic properties may be included in one or all of the following three lists: The DC Inventory of Historic Sites is a listing of properties designated by the Historic Preservation Review Board or its predecessor, the Joint Committee on Landmarks. First established in 1964, the Inventory now includes more than 500 historic landmarks and more than three dozen historic districts with approximately 23,600 buildings. The National Register of Historic Places is the Federal government's list of historic landmarks and historic districts nationwide. The National Register was established by the National Historic Preservation Act of 1966, and is maintained by the National Park Service, U.S. Department of the Interior. National Historic Landmarks are properties designated by the Secretary of the Interior for their outstanding integrity and significance to the nation as a whole. They are selected by the National Park Service, and cannot be designated by other parties. National Historic Landmarks are automatically entered on the National Register. The Historic Preservation Review Board (and its staff, the Historic Preservation Office) maintains the DC Inventory of Historic Sites. You may call the Historic Preservation Office to determine whether or not a building is located within a historic district, or is an individually designated historic landmark. The HPO also provides bound copies of the DC Inventory and a map of the city depicting the boundaries of each historic district.