The Capital Crescent Trail starts at the end of Water Street in the Georgetown neighborhood of Washington, DC and goes for 11 miles, ending in Silver Spring, Maryland. The trail is paved for most of the way making it extremely popular with both cyclists and runners. Along part of the stretch between Georgetown and Fletcher’s Cove, the Crescent Trail runs parallel with the C&O Canal Towpath making it a good circuit route. The trail can get crowded on weekends, so go early!
Trail maps are available at: http://www.cctrail.org/index.html