The Karimata Islands are a chain of small islands off the west coast of Indonesian Borneo, the largest of which is (Pulau) Karimata, being about 20 km across (east-west), and situated at (1°37′S108°53′E). Karimata has a wide range of ecosystems, from mangroves and tropical rain forest in the lowlands to montane shrubland on the summit of the c.1000 metre mountain (a spectacular example of the Massenerhebung effect). The mountain is composed of granite.