Celebrate one of Loudoun County's treasures with activities throughout the park including live music, exhibits, games, historic displays and building tours, nature activities, trail hike/bike/walk, moonbounce fun, campfire & marshmallows, concessions and more. Date: Saturday, April 18, 2015. Time: 11 a.m. until 3 p.m. Free admission and free shuttle service in the park. For more information, call 571-258-3700.