A radar of the National Aeronautics Space Administration (NASA) has found long-lost ruins of temples in the jungles at Angkor, Cambodia. In the 12th century, nearly one million people were staying in the city. Scientists at the NASA have located two temple sites that are very close to each other. It implies that the spot was sacred to the Khmer people for many centuries. In December 1996, a NASA's DC-8 jet with specialised radar flew over and spotted a circular mound at the edge of a moat that suggested human settlement. Elizabeth Moore, head of the department of Art and Archaeology at the University of London's School of Oriental and African Studies, went to the mound to explore it. She found partially exposed remains of a 10th century city at Angkor. This city was built 200 to 300 years before Angkor Wat, says Moore.