The Smithsonian Institution Building or "Castle" on the National Mall is the Institution's headquarters

The Smithsonian Institution is an educational and research institute and museum complex. Most of the institution is in Washington, D.C., but its 19 museums, zoo, and eight research centers include sites in New York City, Virginia, Panama, and elsewhere. It has over 137 million items in its collections.

A monthly magazine published by the Smithsonian Institution is also named the Smithsonian.