Prasat Kamphaeng Yai is situated in Amphoe Utumphorn Phisai in the province of Sisaket, northeastern Thailand. It is a Khmer monument. According to one inscription on a doorjamb of an eastern gopara (gate) of the eastern gallery surrounding the monument, it was founded in Hinduism.The inscription is composed of about 35 lines in Khmer language which reports the purchase of pieces of land in 1042 A.D. by Vra Kamraten An Sivadasa and three other dignitaries. These pieces of land were marked and dedicated to the sanctuary of Vrddhesvara (Siva). After listing the names of the slaves dedicated to the sanctuary, the text enumerates the animals and objects given to the former owners, by those who bought the land.

Prasat Phra Viharn is one of the most beautiful ruins of antiquity. Situated at a majestic height on the Dongrek Mountain Range, which marks the frontier between Cambodia and south-east Thailand, it is a Khmer shrine built between the 11th and 13th centuries. A series of sanctuaries and flights of stone stairways leads up the mountain to the temple tower, the centre of the worship of the god Siอa, to whom the shrine was dedicated. The extensive ruins, older than Angkor Wat, are evocatively preserved; roofs and columns have fallen, but the great native stone walls remain, and the massive carvings have been only softened and mellowed by the centuries.