The largest of all the islands is Isle Royale in Lake Superior, which, in addition to its waters and other surrounding islands, is organized as Isle Royale National Park. Isle Royale itself is . The most populated island is Grosse Ile with approximately 10,000 residents, located in the Detroit River about south of Detroit. The majority of Michigan's islands are uninhabited and very small. Some of these otherwise unusable islands have been used for the large number of Michigan's lighthouses to aid in shipping throughout the Great Lakes, while others have been set aside as nature reserves. Many islands in Michigan have the same name, even some that are in the same municipality and body of water, such as Gull, Long, or Round islands.