Sleeping Bear Dunes features immense and magnificent sand dunes, as well as beaches, forests and inland lakes along a 35-mile strip of the southeastern shore of Lake Michigan. Off the coast, the park also includes two undeveloped islands, North and South Manitou Islands, which offer a more remote backcountry experience. The park's famous dunes were sculpted by the advance and retreat of huge glaciers over the last two million years. It is the world's largest collection of fresh water sand dunes, with striking formations that rise up to 400 feet above the surface of the lake.