The Washington and Georgetown Railroad Car House, also known as the Navy Yard Car Barn, or Blue Castle, is an historic building, located at 770 M Street, Southeast, Washington, D.C. The Romanesque Revival building was designed by Walter C. Root in 1891. It was a repair shop for the Washington and Georgetown Railroad. With the change from cable cars to electric streetcars, the building was used as a storage. Then the building was used as a bus garage.The building was added to the National Register of Historic Places on November 14, 2006. A charter school leases space there. Redevelopment is planned. In 2014, National Community Church bought the property.
