The moody and potent waters of the Great Northern Sea, Lake Superior, alternately lap and pound at the shores of an island formed by ancient volcanoes and a sandy sea bottom, all ultimately carved by glaciers. Now 209 square miles of rocky terrain featuring forests, lakes, bogs, and swamps, it is home to three packs of wolves and a few hundred moose. This designated national wilderness area and UNESCO International Biosphere Reserve features 165 miles of trails and 36 campgrounds, and includes 450 smaller islands in protected waters three times as expansive as its land area. This is Isle Royale, the least visited national park in the lower 48 states. And it all awaits adventurous hikers, campers, boaters, and paddlers.

Isle Royale, in Michigan, is the least visited national park in the lower 48 states. Steven Schremp/Shutterstock