Located in Northwestern Cambodia, Angkor was possibly founded around the Ninth Century AD by King Jayavarman II. Angkor grew to be a vast city which was the centre of the Khmer Empire which controlled most of south east Asia from around 900 to 1500AD. In 1432 the Khmers abandoned Angkor after attacks by neighbouring Thais. The most beautiful and most famous monument in the city is Angkor Wat, the world's largest religious building. Taking 37 years to complete and involving the labour of an estimated 50,000 artisans, workers and slaves, it covers an area of about 81 hectares and is surrounded by a moat 200 metres wide. The complex consists of five towers, which are presently shown on the Cambodian national flag. These towers are believed to represent the five peaks of Mount Meru, the Home of Gods and Center of the Hindu Universe. The Temple of Angkor Wat was dedicated to the Hindu God Vishnu but with the decline of the Ancient Khmer Empire, Angkor Wat was turned into a Buddhist Temple. Although nature presents the greatest threat to Angkor's ancient buildings, the theft of artworks is a huge problem. Carved stone heads and other statues are being systematically removed. In just one week of 1993 five stone heads vanished from one of the causeways to Angkor Thom. In 1992, the UNESCO World Heritage Committee declared the monument, and the whole city of Angkor, a World Heritage Site.