Tranquil grassy area featuring a promenade for walking & biking, plus scenic views & overlooks. The park links 225 miles of parkland along the Potomac River stretching from Cumberland, Maryland, to Mount Vernon, Virginia. The park has notable design elements like the labyrinth, beautiful fountain (seasonal), and charming rain gardens. Rates: $2/hour, Monday through Saturday from 7 a.m. to 10 p.m. Sundays and holidays free!