Almost all moais were carved out of distinctive, compressed, easily worked volcanic ash. The largest one weights up to 165 tons, and its height is almost 22 meters. Some upright moai have become buried up to their necks by shifting soils.

This massive production of megalithic works on an island that is absolutely barren, with just grass, immediately captures our imagination. How did it all happen? Who built these statues? And why did they build them?

Some scientists suggest that Easter Island inhabitants, the Rapanui, came from Polynesia. But similarities to Indian stone statues around Lake Titicaca in South America are striking. Is this accidental or not? Scholars are unable to definitively explain the function and use of the moai statues. Some of them suggest that the statues were symbols of authority and power, both religious and political.

One of the biggest riddles about Easter Island is how the statues ‘traveled’ from the quarry to their platforms or ahus, sometimes as far as 20 or 25 kilometres away? Rapa Nui legend has it that the moai "walked from the quarry”. But less than one third of all carved moai actually made it to a final ceremonial ahus site. Was this due to the inherent difficulties in transporting them? Were the ones that remain in the quarry deemed culturally unworthy of transport? Or had the islanders run out of the resources necessary to complete the Herculean task of carving and moving the moai?

Easter Island is more well known as Te-Pito-O-Te-Henua, meaning ‘The Navel of the World’ and as Mata-Ki-Te-Rani, meaning ‘Eyes Looking at Heaven’. These ancient names and a host of mythological details point to the possibility that the remote island may once have been both a geodetic marker and the site of an astronomical observatory of a long forgotten civilization.