Few places have caused so much speculation about the past as Easter Island with its nearly 900 stone statues. Some of the "heads" are up to 65 feet long and weigh many metric tons. How the statues were made and moved provoked wild speculation. The islanders themselves say that a magical force called "mana" was used to move them. This, their size, and their orientation looking seaward caused Von Daniken to suggest that extraterrestrials assisted. More down to earth explanations have also been fanciful. The 1947 Kon Tiki expedition of Thor Heyerdahl, followed by his excavations as described in Aku Aku tried to demonstrate that Easter and many of the Pacific islands were inhabited by ancient Peruvians who rode the ocean currents to the island. This implicitly racist statement suggests that the islanders were not themselves capable of developing such a level of culture.
Recent work by Jo Anne Van Tillburg, David Steadman and others using excavation and computer simulation suggests that the statues were easily made and that they could have been transported some distance on wooden rollers. Using oral tradition and environmental reconstruction, archaeologists now recognize that the island was once palm-covered. The statue construction and movement was related to environmental destruction on the island, as well as to internal warfare.