Prince William Forest Park - http://www.nps.gov/prwi

Established in 1936, the 15,000 acre Prince William Forest Park is the largest protected natural area in the Washington, D.C. metropolitan region. The park is the largest example of Piedmont forest in the National Park System. The park also protects the Quantico Creek watershed and is a sanctuary for numerous native plant and animal species.

A variety of recreational opportunities are available, which include wildlife viewing, 37 miles of hiking trails, and 21 miles of bicycle accessible roads and trails. Several tent camping options, including family, group, and backcountry camping are available as well as rustic cabin camping, and a full-service, concessionaire-operated RV campground, are available.

Cultural resources located in the park are also varied. They include the remnants of Joplin and Hickory Ridge, two small communities existing prior to the park’s establishment and the works of the Civilian Conservation Corps (CCC), who built facilities, roads and lakes through the park during the 1930s. The Office of Strategic Services (OSS), America's first intelligence agency, used the park for training spies and radio operators between 1942 and 1945.