A National Historic Landmark (NHL) is a building, district, site, structure, or object that is officially recognized by the United States government for its historical significance. All NHLs are listed in the National Register of Historic Places. Out of more than 80,000 U.S.-listed historic places, however, only about 2,430 are NHLs. NHLs are designated by the United States Secretary of the Interior because they are:
- Sites where events of national historical significance occurred;
- Places where prominent persons lived or worked;
- Icons of ideals that shaped the nation;
- Outstanding examples of design or construction;
- Places characterizing a way of life; or
- Archeological sites able to yield information.
A National Historic Landmark District (NHLD) is a historic district that is recognized as an NHL. It may include contributing structures or other elements, and non-contributing ones.
