The National Museum of the U.S. Navy presents a walking tour of the Washington Navy Yard!   This tour offers a chance to explore the Washington Navy Yard and its 219-year history.  Attendees will visit the original Watch Box, hear the true story behind Dahlgren's encased leg, and more.   For more information and to register, e-mail Thomas Frezza at thomas.freeza@navy.mil or call 202-433-4995.