Prasat Ta Muean Thom (in Thai: ปราสาทตาเหมือนธม) is an ancient Hindu sanctuary dedicated Shiva. The temple was built in the era of the ancient Khmer empire Kambuja and is located at the edge of the Dangrek (Dongrak) Mountain Chain next to an ancient travelling route coming up from Angkor. If there were no trees in the mountain slopes in front of the temple an observer would have a splendid view over the Cambodian lowland towards south. From the gates of the temple one would be able watch travellers on the ancient road from the capital city Angkor arriving to an ancient reservoir below to water their elephants and oxen. And travellers coming from the south would from their point of view have seen the spires of Ta Muean Thom as a land-mark from many miles away.
At the foot of the mountains another ancient building, Prasat Chan, would be visible from above and the road from Angkor would on the last stretch before ascending be seen as paved into an 4 meter wide elevated laterite road. After having ascended the Chong Ta Muean mountain pass and passed Prasat Ta Muean Thom we find two more temples: Prasat Ta Muean Tot and Prasat Ta Muean, which both are built by the Mahayan Buddhist Emperor Jayavarman VII nearly two centuries later than Prasat Ta Muean Thom.
Ta Muen Thom is dedicated the Hindu god Shiva and believed to have been built in the beginning of the 11th century. Shivaite temples always host a linga, the phallic symbol of Shiva. One unique feature of Prasat Ta Muean Thom is that it is hosts a 'natural Linga' of the Svāyambhuva (savayambhu) type: ''Svāyambhuva means 'self creating', and a Svāyambhuva linga is considered particularly sacred.'' (Briggs, p. 55, The Ancient Khmer Empire). A famous Svāyambhuva linga is the Phu Kao mountain spire at Vat Phou (Wat Phu) in Champassak province, southern Laos. A little known example is hosted in Prasat Ta Khwai (Ta Krabey, Preah Eisei, Ta Sawai) also at the edge of the Dangrek Mountains and only 11.2 km east of Ta Muean Thom. The orientation between the two Svāyambhuva lingas is only a few degrees from cardinal.