Nan Madol: Ceremonial Centre of Eastern Micronesia

Off Pohnpei's south-east shore, more than 100 artificial islets rise from the lagoon on foundations of basalt and coral boulders — Nan Madol, seat of the Saudeleur dynasty. Between 1200 and 1500 CE its rulers built stone palaces, temples and tombs on a scale unmatched in the Pacific islands. UNESCO inscribed the ruins in 2016 and simultaneously placed them on the Danger List, as silt-fed mangroves slowly overrun the megalithic walls.