Virginia Beach is home to 210 city parks, encompassing over 4,000 acres, including neighborhood parks, community parks, district parks, and other open spaces. Each park is unique and offers something for everyone, from wide open spaces to playgrounds, picnic shelters, and ballfields. Mount Trashmore Park is clearly visible from I-264 when traveling to the oceanfront. The park is 165 acres. The hill is 60 ft high and over 800 ft long, and was created by compacting layers of solid waste and clean soil. It is the highest point in Virginia Beach. The park also features two lakes: Lake Windsor and Lake Trashmore. Lake Trashmore is stocked with fish, but is unsanitary to fish in. Residents can also take advantage of a skate park. Another major park in the city is Great Neck Park, a 70 acres park located in the Lynnhaven District. Facilities include five large group shelters, mini-shelters, family picnic tables and grills, three playgrounds, horseshoe pits, volleyball courts, vending machines, walking trails, four baseball fields, as well as a gazebo located at the end of a scenic walkway overlooking the Lynnhaven River. The Back Bay National Wildlife Refuge, established in 1938, is an 8,000-acre fresh water refuge that borders the Atlantic Ocean on the east and Back Bay on the west. The barrier islands feature large sand dunes, maritime forests, fresh water marshes, ponds, ocean beach, and large impoundments for wintering wildfowl. It is managed by the U.S. Fish and Wildlife Service.