'Coral houses' are dotted throughout the Pacific. Now, scientists know exactly when they were built

'Coral houses' are dotted throughout the Pacific. Now, scientists know exactly when they were built

The Mangareva Islands are about 1,600 kilometers southeast of Tahiti in French Polynesia. They get their name (which means "floating mountains") from the way the sea spray breaking on the surrounding coral atolls, or motu, causes the ancient volcanic peaks to appear as if they are floating above the waves.