At Maurice K.Goddard State Park, 684 Lake Wilhelm Rd, Sandy Lake, the lake stretches over 1,860 acres. Nature lovers often say this park feels more like Canada than central Pennsylvania, and they are not wrong. Greenwood Furnace State ParkGreenwood Furnace State Park is the rare place where history and nature share equal billing. Swimming is popular, and the beach area is one of the nicer ones in the Pennsylvania state park system. Locust Lake State ParkLocust Lake State Park flies under the radar compared to some of Pennsylvania’s bigger parks, and that is honestly great news for anyone who visits.