Acadia National Park is a national park of the United States located along the mid-section of the Maine coast, southwest of Bar Harbor. The park includes about half of Mount Desert Island, part of the Isle au Haut, the tip of the Schoodic Peninsula, and portions of sixteen smaller outlying islands. The park contains the tallest mountain on the Atlantic Coast of the United States, exposed granite domes, glacial erratics, U-shaped valleys, and cobble beaches.