Nan Madol is an archaeological site adjacent to the eastern shore of the island of Pohnpei, now part of the Madolenihmw district of Pohnpei state in the Federated States of Micronesia in the western Pacific Ocean. Nan Madol was the capital of the Saudeleur dynasty until about 1628. The city, constructed in a lagoon, consists of a series of small artificial islands linked by a network of canals. The site core with its stone walls encloses an area approximately 1.5 by 0.5 kilometres and it contains 92 artificial islets—stone and coral fill platforms—bordered by tidal canals.

Pohnpei is an island of the Senyavin Islands which are part of the larger Caroline Islands group. It belongs to Pohnpei State, one of the four states in the Federated States of Micronesia (FSM). Major population centers on Pohnpei include Palikir, the FSM's capital, and Kolonia, the capital of Pohnpei State. Pohnpei is the largest island in the FSM, with an area of 334 km2 (129 sq mi), and a highest point of 782 m (2,566 ft), the most populous with 36,832 people, and the most developed single island in the FSM.