One of Thailand's oldest cities, Lopburi developed during the Dvaravati period (6th to 10th centuries), when it was known as Lavo. What remains today is the architecture and artwork of the subsequent Khmer and Ayuthaya empires. King Narai (r 1657–88) made it a second capital and hosted many foreign dignitaries here.
But it's the furry modern-day residents that really define the city. Hundreds of monkeys live in and around two of the major ruins and most visitors, both Thai and foreign, come here specifically to experience the monkey mayhem.
Read more: http://www.lonelyplanet.com/thailand/lopburi-province/lopburi/introduction#ixzz4DyhCCJU2