The Anacostia Riverwalk trail is a relatively recent addition to the D.C. recreation and running scene. About 1.5 miles south of the Capitol, it is a wonderfully constructed, continuous 20-mile trail on both sides of the Anacostia River, with good loop options enabled by several bridges. The area has been revitalized, with an improved park and several sports stadiums. About 12 miles of the trail are open and heavily used. NE. This map has more information. Major sights include the Navy Yard, ballpark, and stadiums on the north side, Anacostia Park on the south side.
We’ve mapped out an 8-mile loop on both sides of the river, between South Capitol St. and Benning Rd. There are four bridges on this route, so you can adjust the distance. There are many other sections of the trail that provide opportunities for an add-on, especially north of Benning Rd. This Capitol Riverfront Map also shows connectors to the Mall (1.5 miles north) and Tidal Basin.