Lake Fairfax Park is a park in Reston, Fairfax County, Virginia, USA owned and maintained by the Fairfax County Park Authority. Contained within the park is the 18-acre Lake Fairfax. The park also offers a waterpark, carousel, picnic areas, campgrounds, trails, playground and more. The park has also played host to music festivals, including Lollapalooza and The HFStival.