The Malaysian states of Sabah and Sarawak make up twenty six percent of the island. Borneo is often imagined as a mountainous island, yet half of the island consists of a waterlogged coastal environment, no more than 150 m above sea level. Borneo is also home to some of the oldest rainforests in the world, now fragmented, they are the custodians of rare and endemic species, including the Bornean orangutan.