Its surface area is 535,4 km2 (206,7 sq mi). It is located in the northwestern part of the lake. Surrounded by over 400 smaller islands, it hosts an Isle Royale National Park. Park was established on April 3, 1940 and declared a UNESCO International Biosphere Reserve in 1980. It is visited by about 25 thousand tourists annually, making it the least-visited national park in the contiguous United States.
