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 Island is the largest with an area of , and a highest point of , 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. Pohnpei contains a wealth of biodiversity. It is one of the wettest places on Earth with annual recorded rainfall exceeding each year in certain mountainous locations. It is home to the ka tree (Terminalia carolinensis) found only in Pohnpei and Kosrae. The highest point of the island is Mount Nanlaud at 772 or 782 metres. Pohnpei is home to several dozen bird species including four endemic species, the Pohnpei lorikeet, the Pohnpei fantail, the Pohnpei flycatcher and the long-billed white-eye. A fifth endemic, the Pohnpei starling, is thought to have recently gone extinct. The only land reptiles are a few species of lizard. Originally the only mammals were bats. Pigs, rats and dogs were introduced; pigs have become feral. The lagoons are rich in fish, molluscs, turtles and other marine fauna. Pohnpei belongs to the tropical rainforest climate zone (Köppen: Af). It is one of the wettest places on Earth with an average annual recorded rainfall of in towns along the coast and about each year in certain mountainous locations. Nan Madol The natives of Pohnpei, especially the 'older' generations, often refer to events in their past as having occurred, e.g.