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.