Wissahickon Valley Park is a large urban park that is located in Northwest Philadelphia, Pennsylvania. It protects 2,042 acres of woodland surrounding the Wissahickon Creek between the Montgomery County border and the Schuylkill River. For several miles, the creek winds through a dramatic wooded gorge known as the Wissahickon Valley, a National Natural Landmark. Forbidden Drive runs the length of the valley, a car-free gravel road popular for walking, running, cycling, and horseback riding.