The island has several rivers, including the Alexandra, Amrit Kaur,
Dogmar and Galathea. Virtually all rivers flow in a southern or
southwesterly direction, which is indicative of the general slope of the
terrain across the island.
There are undulating hills throughout the island, with the main range running in a north-south orientation. Mount Thuillier, which is part of this range, has the highest elevation of any point in the Nicobars, at 642 m above sea level. Indira Point was submerged in the 2004 tsunami.