National Historic Landmarks (NHL) are buildings, districts, sites, structures, and objects (almost always) within the United States or its insular areas and designated by the United States Secretary of the Interior because they are:

• sites where events of national historical significance occurred;
• places where prominent Americans 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.

All NHLs are also listed on the National Register of Historic Places, but not all Register properties are NHLs.

See the main article for more informantion.

National Register of Historic Places | Protected areas of the United States