Legend says Tangaroa, the divine god of the sea, was the first inhabitant of Atiu. Captain Cook was the first European to sight the island on 31 March, 1777.
Atiu was once a volcano which sank leaving a coral reef around a low plateau. 100,000 years ago, volcanic action pushed it up killing the reef and creating a razor sharp band of coral called a makatea. The makatea runs around the island ranging in width from 50 to 100 metres. Low cliffs, 3 to 6 metres high surround the island, but there are many recesses in which small sandy coves are found. There are limestone caves all over the makatea and some are used as ancient burial sites. Tourism is still in its infancy, but the island is easily accessible now by air.