Borneo

THE ISLAND OF BORNEO is the largest island of theMalay archipelago and the third-largest island in the world (after GREENLAND and PAPUA-NEW GUINEA), covering 287,420 square mi (736,974 square km). It is also one of the least explored places on Earth and retains much of the mystery for today’s tourists that it did for anthropologists and adventurers of the 19th century. Borneo is not a single political unit; rather, it is divided among three countries: 72 percent of the island, known as Kalimantan, is a province of INDONESIA.

The rest forms the two eastern provinces of MALAYSIA, Sabah and Sarawak, plus the small independent sultanate of BRUNEI. Unlike most of its island neighbors, Borneo is not entirely volcanic in origin, but formed of ancient igneous rock. It is seen more as an extension of the continental landmass of Southeast Asia, separated only by the Sunda Sea, which is very shallow (656 ft or 200 m) and was probably dry land in the geologically recent past. This is in contrast to the deep plunges of the waters to the east and south of the island, the Sulu and Celebes seas, and the Selat Makasar.

Borneo is crossed by two main mountain chains, which roughly divide the island into four watersheds. Three of these cover Kalimantan, while the fourth, that of the northwest, waters Sabah, Sarawak, and Brunei. The main range, like a backbone, crosses the island diagonally from southwest to northeast and consists of the Kapuas and Iran ranges—which form the boundary between the Indonesian and Malaysian parts of the island—continue in the south as the Schwaner range.

These ranges have several peaks over 6,600 ft (2,000 m), but the highest mountain on the island (and in Southeast Asia), Kinabalu (13,533 ft or 4,101 m), stands on its own at the far northern point of the island. The volcanic Kinabalu is one of the leading spots in the region for tourists, drawn to its hot mineral springs and exotic wildlife, including the Rafflesia, the largest flower in the world (up to 66 in or 170 cm in diameter).