Madagascar, an Indian Ocean island, has a rugged spine of mountains running north-south, with the Tsaratanana Massif peaking at Maromokotro (2,876 m)—the island's highest—formed by tectonic uplift 100 million years ago during Gondwana breakup. The Ankaratra Range in the center reaches 2,643 m with volcanic craters and crater lakes like Tritriva (0.1 km²). Southern Andringitra Mountains hit 2,658 m, featuring granite inselbergs and Tsingy de Bemaraha's limestone pinnacles up to 100 m. These ranges divide humid east from dry west, hosting 90% endemic species in Ranomafana National Park. Rivers like the Mangoky (700 km) carve canyons, supporting lemurs and baobabs in six biosphere reserves.
