Watch on Soap2day. At the height of its power between the 9th and 15th centuries, Angkor was a resplendent city, considered the most extensive urban complex of the pre-industrial world. But by the late 16th century, the empire was in its death throes. The people of Angkor left not a single word explaining their kingdom's collapse. Come along on this giant screen adventure to unveil the mysteries behind this lost jewel of Cambodia!