Ometepe is an island formed by two volcanoes rising from Lake Nicaragua in the Republic of Nicaragua. Its name derives from the Nahuatl words ome (two) and tepetl (mountain), meaning two mountains. It is the largest island in Lake Nicaragua as well as the largest volcanic island inside a fresh water lake in the world. The two volcanoes, Concepción and Maderas, are joined by a low isthmus to form one island in the shape of an hourglass. Ometepe has an area of 276 km².