Corsica was formed through volcanic explosions, and is the most mountainous island in the Mediterranean.
It is 183 kilometres (114 mi) long at longest, 83 kilometres (52 mi) wide at widest, has 1,000 kilometres (620 mi) of coastline, more than 200 beaches, and is very mountainous, with Monte Cinto as the highest peak at 2,706 metres (8,878 ft) and 20 other summits of more than 2,000 metres (6,600 ft). Mountains comprise two-thirds of the island, forming a single chain. Forest comprises 20% of the island.
Approximately 3,500 km2 (1,400 sq mi) of the total surface area of 8,680 km2 (3,350 sq mi) is dedicated to nature reserves (Parc Naturel Régional de Corse), mainly in the interior. Corsica contains the GR20, one of Europe's most notable hiking trails.
The island is 90 kilometres (56 mi) from Tuscany in Italy and 170 kilometres (110 mi) from the Côte d'Azur in France. It is separated from Sardinia to the south by the Strait of Bonifacio, a minimum of 11 kilometres (6.8 mi) wide.