Just 13 miles long and seven miles wide, Easter Island rises like a fortress from the waves, surrounded by thousands of miles of ocean in every direction. People first arrived here less than 1,000 years ago. Most of what we know about their civilisation can only be pieced together from the relics that remain. It is a strange and desolate place. The most striking features in this bleak and windswept landscape are the hundreds of giant stone statues, known as moai, thought to be carved in the likeness of chiefs or ancestors. It's difficult to believe that an advanced culture capable of carving and erecting these monoliths grew up in such a barren landscape. The truth is, it didn't. When those first colonisers discovered Easter Island, this was a paradise. These empty cliffs were once home to the largest seabird colonies in the South Pacific.