It was the size of modern LA, a masterpiece of civil engineering. Forests were stripped and rivers removed to make way for temples, palaces and markets. Then, in a development that has long perplexed archaeologists, Angkor suddenly vanished. Now a recent study by the University of Sydney is re-examining Angkor using radar remote-sensing data from NASA. As archaeologist Damien Evans explains, the team's findings give a stark warning to Cambodia's corrupt and greedy rulers, and to modern societies worldwide. 'We are facing similar issues', says Evans, 'The same mistakes are being repeated today'.