A thousand years ago, the Khmer people of Cambodia built an empire and their capital was the great city of Angkor, with its centrepiece being Angkor Wat - a vast temple complex covering an area more than four times the size of the Vatican City. In the first of this two-part programme, an international team of archaeologists and scientists use revolutionary technology to reveal the true scale and extent of the lost metropolis and find out how its people lived and died.
