The high islands of Chuuk's central lagoon are studded with Japanese fortifications from the Second World War. Wartime lighthouses, gun emplacements, cave networks, command bunkers, and the remnants of airfields can all be found with the help of a local guide, and many are accessible on foot via the island trails.
The hilltop lighthouses were positioned for maximum visibility across the lagoon and still offer panoramic views over the atoll and its barrier reef. Some of the cave complexes were used as hospitals and command posts; others housed ammunition stores. The overgrown runways on Weno (Moen) island, the main administrative island, are still visible. Local guides — often the grandchildren of those who lived through the occupation — can give context that no signage provides. These relics, combined with the underwater wrecks, make Chuuk a singular site of WWII Pacific history.