 The Maldives has no hills, but some islands have dunes which can reach above sea level, like the NW coast of Hithadhoo (Seenu Atoll) in Addu Atoll.The islands are too small to have rivers, but small lakes and marshes can be found in some of them.On average, each atoll has approximately 5 to 10 inhabited islands; the uninhabited islands of each atoll number approximately 20 to 60.