As of 2004, the Navy Yard houses a variety of activities. It is the main office of the Naval District Washington, and houses numerous support activities for the fleet and aviation communities. The Navy Museum welcomes visitors to the Navy Art Collection. Its displays of naval art and artifacts trace the Navy's history from the Revolutionary War to the present day. The Naval History and Heritage Command is housed in a complex of buildings known as the Dudley Knox Center for Naval History. Leutze Park is the scene of colorful ceremonies.