The Maldives archipelago is located on the Chagos-Laccadive Ridge, a vast submarine mountain range in the Indian Ocean; this also forms a terrestrial ecoregion, together with the Chagos Archipelago and Lakshadweep. With an average ground-level elevation of 1.5 metres (4 ft 11 in) above sea level, it is the world’s lowest-lying country, with even its highest natural point being one of the lowest in the world, at 5.1 metres .