Nan Madol in the context of Madolenihmw

An artificial island or man-made island is an island that has been constructed by humans rather than formed through natural processes. Other definitions may suggest that artificial islands are lands with the characteristics of human intervention in their formation process, while others argue that artificial islands are created by expanding existing islets, constructing on existing reefs, or amalgamating several islets together. Although constructing artificial islands is not a modern phenomenon, there is no definite legal definition of it. Artificial islands may vary in size from small islets reclaimed solely to support a single pillar of a building or structure to those that support entire communities and cities. Archaeologists argue that such islands were created as far back as the Neolithic era. Early artificial islands included floating structures in still waters or wooden or megalithic structures erected in shallow waters (e.g. crannógs and Nan Madol discussed below).

In modern times, artificial islands are usually formed by land reclamation, but some are formed by flooding of valleys resulting in the tops of former knolls getting isolated by water (e.g., Barro Colorado Island). There are several reasons for the construction of these islands, which include residential, industrial, commercial, structural (for bridge pylons) or strategic purposes. One of the world's largest artificial islands, René-Levasseur Island, was formed by the flooding of two adjacent reservoirs. Technological advancements have made it feasible to build artificial islands in waters as deep as 75 meters. The size of the waves and the structural integrity of the island play a crucial role in determining the maximum depth.

Pohnpei (formerly known as Ponape or Ascension, from Pohnpeian: "upon (pohn) a stone altar (pei)") 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 km (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.

Pohnpei is home to the megaliths and ruined city of Nan Madol, built of artificial islands off the island's eastern shore beginning in the 8th or 9th century. An important archaeological site, it was declared a national historic site in 1985.

6°51′N 158°13′E / 6.850°N 158.217°E / 6.850; 158.217

The Saudeleur dynasty (Pohnpeian: Mwehin Sau Deleur, "Period of the Lord of Deleur"; also spelled Chau-te-leur) was the first organized government uniting the people of Pohnpei island, ruling from c. 1100-1200 CE to c. 1628 CE. The era was preceded by the Mwehin Kawa (Period of Building) or Mwehin Aramas (Period of Peopling), and followed by Mwehin Nahnmwarki. The name Deleur was an ancient name for Pohnpei, today a state containing the capital of the Federated States of Micronesia.