 Construction of Nan Madol, a megalithic complex made from basalt lava logs in Pohnpei, began in around 1180 CE.This was followed by the construction of the Leluh complex in Kosrae in around 1200 CE.The earliest known contact with Europeans occurred in 1521, when a Spanish expedition under Ferdinand Magellan reached the Marianas This contact is recorded in Antonio Pigafetta's chronicle of Magellan's voyage, in which he recounts that the Chamorro people had no apparent knowledge of people outside of their island group.