Cumberland Island National Seashore preserves most of Cumberland Island in Camden County, Georgia, the largest of Georgia's Golden Isles. The seashore features beaches and dunes, marshes, and freshwater lakes. The national seashore also preserves and interprets many historic sites and structures. Instrumental in the creation and preservation of the seashore were several conservation organizations including the Sierra Club and the Georgia Conservancy. The island is only accessible by boat.