Based on elevation and nature of the terrain five geomorphic regions can be identified: the coastal fringe, the central highlands, the south-west country, the east and southeast, and the north central lowlands.

The central massif from which headwaters of all Sri Lanka's major rivers originates, is a compact physiographic unit bounded on the south by a high mountain, the Worlds End. The topography of the southwest; the other part of Sri Lanka's Wet Zone is characterized by long parallel ridges cut by the rivers beginning in the hill country. The eastern and south eastern lowlands are characterized by rolling hills, undulating plains and isolated residual hills. The coastal fringe has important fisheries and the region contains large parks and wildlife refuges that are home for wild elephants. The north central lowlands are somewhat similar to those in the east. In this region, the country's hydraulic civilization flourished.