Known as Kalimantan by the Indonesians, the island of Borneo is the third largest in the world. Lying astride the equator, it has one of the richest biodiversities of any place on earth, with 15,000 flowering plants and more than 220 terrestrial mammals, for example. The most well-known of the latter is the orang-utan. The cultural diversity is also impressive, with more than 30 sub-ethnic groups of Dayak people - some of whom have a fairly bloodthirsty past, with regular intertribal wars and ritual headhunting. The island's highest point is Mount Kinabalu (4095m / 13,435ft), situated in the region of Sabah, one of 2 northern regions (the other is Sarawak), which are governed by Malaysia. For any adventure traveller visiting this part of the world, the 2-day trek to the top of this iconic peak is a must.