The historical town of Si Thep is located in the Phetcahbun province of Thailand. The archeological site was inhabited from the 3rd to 5th century BC until the 13th century, covering historical periods from late prehistory through Dvaravati to the golden age of the Khmer Empire. Si Thep was one of the largest known city-states that emerged in central Thailand in the first millennium. The site was discovered in the early 1900s and appointed a national historical site in the 1980s.
The historical town of Si Thep was declared a UNESCO site in September 2023. It is the newest addition of Thailand to the list of cultural World Heritage Sites.
The historical site of Si Thep consists of three components: a distinct twin-town site, the Khao Klang Nok ancient monument; and the Khao Thamorrat Cave ancient monument. These historical structures represent the architectural artisanry and religious diversity of the Dvaravati Empire that emerged in Central Thailand, showcasing influences from India. The localization of the Hindu artistic traditions gave way to a distinctive artistic tradition known as the Si Thep School of Art, which influenced other civilizations in Southeast Asia. More than 110 significant monastery sites have been identified at Si Thep.
The massive Khao Klang Nok is a Buddhist pagoda representing the Dvaravati cosmological belief. With a width of 64 meters and a height of 20 meters, it is the largest surviving Dvaravati monument. There are four entrances with stairways on each side of the base. The base of the monument was decorated with a replica of Prasats, an ornate roof structure, influenced by Indian art.
Khao Thamorrat Cave is a unique Mahayana Buddhist cave monastery that displays important examples of Dvaravati art. Khao Thamorat is a mountain that stands 15 km away from Si Thep, and inside the cave of the mountain, there are a total of 11 bas-relief sculptures of the Buddha and Bodhisattva.