Nan Madol

6.8412°N, 158.3349°E.

Ruined ceremonial city built on 92 artificial islets in a tidal coral lagoon off the southeast coast of Pohnpei, Federated States of Micronesia. Construction occurred between approximately 1180 and 1628 CE, primarily under the Saudeleur dynasty. The islets are built from columnar basalt prisms — long, hexagonal natural columns — stacked log-cabin style; some single columns weigh up to 50 tonnes. Total estimated mass: 750,000 tonnes of basalt. The nearest documented quarry, on Sokehs island 50 km away, contains identical columnar basalt; how the columns were transported and lifted onto the reef has never been adequately explained. The royal mortuary islet of Nandauwas is enclosed by walls 7.5 metres tall. Pohnpeian oral tradition attributes the construction to twin sorcerers who flew the stones into place.

A Pacific island culture stacked fifty-tonne basalt logs into a city floating on a coral reef — and the only surviving explanation involves flying them.