The Masalembu Islands lie in the Java Sea to the north of Madura, about halfway between Madura and Borneo. The Madurese language is spoken on the islands. The three main islands are Masalembu Island, Masakambing Island, and Karamian Island. The land area of the district is 40.85 square km, and they had a population of 20,687 people in the 2000 census