The Piton des Neiges (Snow Peak) is a massive 3,069 m (10,069 ft) shield volcano on Réunion, one of the French volcanic islands in the Mascarene Archipelago in the southwestern Indian Ocean. It is located about 800 kilometres (500 mi) east of Madagascar. Piton des Neiges is the highest point on Réunion and is considered to be the highest point in the Indian Ocean. The volcano was formed by the Réunion hotspot and emerged from the sea about two million years ago. Now deeply eroded, the volcano has been inactive for 20,000 years and is surrounded by three massive crater valleys, the Cirques. Piton des Neiges forms the northwestern two thirds of Réunion, with the very active Piton de la Fournaise comprising the rest. Despite its name, snow (French: neige) practically never falls on the summit.
The volcanic island is considered to be about three million years old (Pliocene); the other two islands in the archipelago, Mauritius and Rodrigues, are 7.8 million (Miocene) and 1½ million (Pleistocene) years old, respectively. The island possesses a high endemism of flowering plants (about 225); this has justified the creation of a biological reserve on the lower slopes of the Piton des Neiges.