town walls in nan douwas, nan madol: prehistoric ruined stone city. pohnpei, micronesia, oceania.

ancient archaeological archeology architecture basalt caroline castle city civilization culture federated fort fortification fortress gates heritage historical island islands landmark landscape madol megalith megaliths micronesia monument mysterious nan ocean oceania old outdoor pacific pohnpei prehistoric rock rocks ruin ruined site slabs states stone stronghold sunny temple tourism town travel unesco vacation world