Such astonishing diversity is partially a product of Sulawesi’s tortured geography.

The island’s four outstretched "arms" are in a sense all separate; they rise from a deep seabed formed by contiguous folds in the earth’s crust but are isolated from one another by steep ravines, dense forests and forbidding peaks.

Unlike many other Indonesian islands, only Sulawesi’s northeastern and southwestern extremities (the Minahasa and Makassar regions) are volcanic, and instead of gently sloping contours and broad plains, most of the island consists of jagged uplands and rugged plateaus lying 500 meter (1,600 feet) or more above sea level.
The central peaks of Sulawesi reach as high as 3,400 meters (11,000 feet). Sulawesi features, steep mountains, deep gorges, fast flowing rivers, blue highland lakes, lush rainforests, Savannah’s and white-sand beaches and a fascinating range of unusual flora and fauna.
Many species of fauna found in Sulawesi can not be found else where in the world, like the black macaque, the babirusa wild boar, the anoa dwarf buffalo, the eccentric maleo bird, the saucer-eyed tarsier, and many beautiful and colorful butterflies. (source: www.asia-planet.net)