Great Falls Park is a small National Park Service (NPS) site in Virginia, United States. Situated on 800 acres (3.65 km2) along the banks of the Potomac River in northern Fairfax County
, the park is a disconnected but integral part of the George Washington
Memorial Parkway. The Great Falls of the Potomac River are near the northern boundary of the park, as are the remains of the Patowmack Canal, the first canal in the United States that used locks to raise and lower boats.
Access the park by exiting Interstate 495 (the Capital Beltway) at Georgetown Pike (Virginia Route 193) and head west 3 miles (4.5 km) to Old Dominion Drive. From there follow the signs north 1 mile (1.5 km) to the park entrance. There is a $5 entrance fee per car for visitors who drive into the park. The park is open only during daylight hours. The park has several viewing platforms that provide visitors with vantage points overlooking the falls. The NPS operates a visitor center near the falls.
Fifteen miles (24 km) of hiking trails encompass the park and follow a small stream known as Difficult Run. A scenic trail near the river travels upstream from a landing at the mouth of Difficult Run, climbs to the top of Mather Gorge and passes the falls, a dam, and a reservoir before ending in Fairfax
County's Riverbend Park. The park contains a large picnic area and sufficient parking for 600 vehicles. On busy weekends all the parking may fill up by early in the morning, creating delays and temporary closures lasting up to several hours. The NPS does not permit camping in the park.