The village of Atiu, with a population of 500, is not on the coast, but in a fertile soil covered depression in the middle of the island. Between the depression and the coast lies the jungle covered makatea plateau about 20-50m asl. Its limits are the so called inner and outer rims. This is where the karstification and the caves can be found.
Text from George Szentes (2004): Caves of the Cook Islands, The British Caver Vol. 127 Spring 2005, pp 1-12, 13 color pictures, 1 bw picture, 1 map. With kind permission of the author.