Fairfax Cross County Trail

By anyone's reckoning, it's a unique and glorious achievement for one American county -- a trail over 40 miles long that connects the entire county from one end to the other: the Fairfax Cross County Trail  runs through some of the county's most scenic areas, beginning in the north at Great Falls National Park on the Potomac River, where it connects with the Potomac Heritage Trail that continues north along the Potomac River to Loudon County. Most of the Fairfax Cross County Trail follows protected stream valleys (the Pohick, Accotink, and Difficult Run stream valleys), extending south to the Occoquan River via Laurel Hill Park, formerly the site of Lorton Prison and its extensive farmlands.

Trail map.