Close up detail of a Moai stone sculpture on Easter Island

Moai sculpture on Easter Island (Easter Island is also known as Rapa Nui). Moai details : On average, these stone giants stand 13 feet high and weigh 14 tons, human heads-on-torsos carved in the male form from rough hardened volcanic ash. The islanders call them 'moai,' and they have puzzled ethnographers, archaeologists, and visitors to the island since the first European explorers arrived here in 1722. In their isolation, why did the early Easter Islanders undertake this colossal statue-building effort? Unfortunately, there is no written record (and the oral history is scant) to help tell the story of this remote land, its people, and the significance of the nearly 900 giant moai that punctuate Easter Islands barren landscape. . (Photo by Jeff Overs/BBC News & Current Affairs via Getty Images)