The National Museum of the United States Navy, or U.S. Navy Museum for short, is the flagship museum of the United States Navy and is located in the former Breech Mechanism Shop of the old Naval Gun Factory on the grounds of the Washington Navy Yard in Washington, D.C., United States. The U.S. Navy Museum is one of ten official Navy museums, and is part of the Naval History & Heritage Command, the official history program of the United States Navy.