Stretching over some 400 square kilometres, including forested area, Angkor Archaeological Park contains the magnificent remains of several capitals of the Khmer Empire of the 9th to the 15th centuries, including the largest pre-industrial city in the world. The most famous are the Temple of Angkor Wat and, at Angkor Thom, the Bayon Temple with its countless sculptural decorations . Angkor Archaeological Park was declared a UNESCO World Heritage site in 1992. At the same time, it was also placed on the List of World Heritage in Danger due to looting, a declining water table, and unsustainable tourism. UNESCO has now set up a wide-ranging programme to safeguard this symbolic site and its surroundings.