National Historic Landmarks are historic places that illustrate the heritage of the United States. Today, just over 2,500 historic places bear this national distinction.

A National Historic Landmark (NHL) is a historic building, site, structure, object, or district that represents an outstanding aspect of American history and culture.

NHLs may:

· be a property with the strongest association with a turning point or significant event in our nation's history.
· be the best property to tell the story of an individual who played a significant role in the history of our nation.
· be an exceptional representation of a particular building or engineering method, technique, or building type in the country
· provide the potential to yield new and innovative information about the past through archeology.

The National Historic Landmarks Program is a Federal designation program.

photograph by Wisconsin Historical Images via Flickr University of Wisconsin Dairy Barn, WI: The University of Wisconsin Dairy Barn located on the campus of the University of Wisconsin, was an internationally recognized leader in agricultural research. The barn complex was the site of the "single grain" experiment that led to the discovery of vitamins and their importance in a healthy diet. This ground-breaking experiment helped to establish the new science of nutrition during the twentieth century.