2/3 of the island of Grande Comore are occupied by Karthala, a still active volcano which culminates at 2360 m. Zoom (double-click) on the crater and you will see a caldera 3 km in diameter.
The last major eruption dated end of 2005. North of the island, another volcano, La Grille is quieter (see the vegetation on it).
The capital of the Union of the Comoros, Moroni, is located on the west coast of Grande Comore.
Other islands in the Indian Ocean