Sundial, calendar and Khmer temples

Astro-archaeology = archaeo-astronomy = Astroarchaeology = archaeoastronomy

Prasat Ta Muean Thom

An ancient Hindu sanctuary at an ancient route from Angkor


Above: North-western tower   Above: A Svāyambhuva linga and Nandin   Above: North-eastern tower.

     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.



Above: Prasat Ta Muean Thom.
Can also written as as Ta Muen, Ta Muan, and Ta Moen.
With courtesy to Google Map:

Basic data for astro-archaeology:
1. Location: N14.34914 E103.26652.
Orientation: Towards south, 171.5 degrees.
Age: Beginning of the 11th century.


     Another unique feature of Prasat Ta Muean Thom is the orientation of the the temple. Most ancient Khmer temples are orientated towards east (but not necessarily cardinal 90 degrees true east) and thereby allowing the raising sun to illuminate the deity in the central sanctuary twice a'year. Those very few Khmer temples orientated otherwise are, when orientated west and north, always orientated cardinally. Those few temples which we know are orientated towards south (Phimai and Ta Muean Thom) are not cardinally orientated, maybe because cardinal south is associated with the Hindu god Yama, a dikpala (Guardian of the Cardinal Directions) who is the ruler of the underworld, judge of the death, and guardian of cardinal south. Neither are Phimai nor Ta Muean Thom orientated straight towards the capital of Kambuja, Angkor. The orientation of Ta Muean Thom is 171.5 degrees, which is 8.5 degrees from cardinally south and 24 degrees of from the orientation towards Angkor.

Above: From north Above: From north Above: Central sanctuary from west
Above: Detail of central tower on the western facade. Above: The central tower with the garbhagriha, the room hosting the linga Above: Circles and squares outside the garbhagriha and the linga.
Above: East of the garbhagriha room a soma-sutra canal leads lustral water (soma) zigzagging towards north-east. Above: An elephant is engraved on the bed-rock next to the soma-sutra with the head oriented towards the flow of the soma. Above: Most of the engraved lives follow the orientation of the buildings; some - as here - are engraved with cardinal orientation.
Above: View towards south and the central sanctuary from a gate in the northern gallery. Above: A 'self created' Svāyambhuva linga is considered particularly sacred.'' Above: Pedestal for inserting a deity and auspicious objects
Above: Head of soma-sutra. Normally the soma is flowing towards north. Above: View towards north and through the northern gallery. Above: View towards north: Pedestal, Shiva's bull Nandin, and the linga, the symbol of Shiva.
Above: Lion pattern Above: Defaced guard (dvarapala) Above: Defaced guard (dvarapala)
Above: Architectonic detail. Above: A rishi (hermit) at a door column. Above: Window in gallery. From NW.
Above: Blind window in northern gallery. Above: Western bannalai, 'library'. Above: Northern gallery
Above: Detail of central tower (se above). Above: Small pond north of the temple. Above: Naga

Above: Southern facades
The staircase south of the facades



The French surveyor Etienne Aymonier visited the area nearly a century ago and apparently noticed neither of the 2 smaller structures Prasat Chan nor Ta Muean dharmasala wrote that the
''biggest ruins of the province of Souren [Surin] are two temples built at less than two miles distance to the west of the passage of Chup Mach [Chong Klang 4 km towards east], on rather flat terrain in the vicinity of the last crest of this plateau of this sudden fault which is called Dangrek mountains and which rises like a wall of three to four hundred metres north of the basin of the Great Lake of Cambodia. These temples, called Ta Mean Thom, 'the big one', and Ta Mean Tauch, 'the small one', stand four hundred metres apart, in a deserted, silent forest which covers several miles in area and the gigantic columns of which support a dark roof of green foliage, mostly belonging to the tree species which the Cambodians call 'sparrow foot', the most durable and lasting wood of all the hard woods of Cambodia.
Ta Mean Thom, the eastern most temple, at sixteen hundred metres only of the rocky crest, was announced, from the foot of the Dangrek [Dongrek], by a staircase which climbs the mountain and which today still serves as a path for bandits rather than for the very rare travellers who dare to penetrate these deserted areas. The locals claim that there are statues of elephants and of crocodiles
at the bottom of this staircase but this has not been verified. The staircase reaching the upper plateau, ends in a road which goes straight to the entrance steps of the temple. This monument faces south.''
... ''the four sculpted doors of which face the points of the compass and are flanked with high relief figures : warriors carrying bludgeons or gracious women holding lotus flowers'' of the central sanctuary has long disappeared or been defaced as shown above.
... the writing on an inscription ''is completely cursive and cannot help in dating this text. The language, rather, allows us to assume that it goes back to the tenth century s'aka.'' [11th century]
Khmer Heritage in Thailand, pgs 224 - 225

The other 3 nearby sanctuaries:

Prasat Chan Prasat Ta Muean Tot Prasat Ta Muean

     Within a distance of only 2-3 km we find 4 sanctuaries: Prasat Ta Muean Thom, Prasat Ta Muean Tot, Prasat Ta Muean, and Prasat Chan.
     Chan is the name of a flower, not Moon, which is transcribed similarly. Ta means granny, Muean is probably derived of the name of the nearby village Ta Mian and could be the name of a person, Thom means 'big', and Tot means 'small'. Prasat means 'temple'. And it should be noted that all names are modern colloquial names.

     Prasat Chan is the first sanctuary a traveller meets when coming from Angkor. We have no certainty for neither the function nor the age of Prasat Chan. Some scholars regard it as one of Jayavarman VII's 17 dharmasalas. Other scholars doubt this. The author doubts because the plan of Prasat Chan is basically different from well-known dharmasalas as for example Ta Muean. And the engraved pattern is different as well. The author tentatively suggest that the structure could have been built by the same hand as Ta Muean Thom, and could maybe have functioned as an 11th century Hindu 'rest-house' or 'house-with-fire' along the ancient route.
     Prasat Chan, the paved road and the reservoir will be surveyed in late 2008.
     Prasat Ta Muean is a typical Jayavarman VII dharmasala of which the Preah Khan inscription counts 17 from Angkor to Phimai. The inscription uses the term agni-sala, which literally means 'house-with-fire'. Dharmasala is a recent European term indicating a place to conduct dharma, Buddhist teaching. The term 'rest-house' has been used as well, which has mislead many readers to conceive the building as a 'guest-house', which is not correct. The building was most likely used for performing religious ceremonies. Mortal did not accommodate in stone structures; they dwelled in shelters of wood and bamboo. The dharmasala consists rectangular building with a tower in the one end and windows on the southern facade. 
     Prasat Ta Muean Tot we are certain of as well because a 'hospital inscription' has been excavated on site, informing us that the sanctuary was used as a Mahayan Buddhist 'hospital-shrine', an arokhayasala, which Jayavarman VII built throughout his empire in late 12th  to the beginning of the 13th century.


 GPS based map made by the author showing the location of the 4 temples and related structures in the area along the ancient route, the Dharmasala Route, where it ascends via the Chong Ta Muean Mountain Pass connecting the Tonle Sap Plateau with the Khorat Plateau.

 The location of Prasat Chan is estimated after a CISARK map. The existence has been mentioned by the Thai border police since my first visit in 2002.
 The location of the ancient route is an estimation based on satellite studies and loaded on my GPS for field verification late 2008.
 A reservoir will be searched for  1 km SE of Prasat Chan; most likely at the creek.
 The green line is based on satellite images and could be a dike, eventually old.


     From a local perspective Prasat Ta Muean Thom is one of four sanctuaries along the Chong Ta Muean Mountain Pass and the ancient 'royal road' coming from south.
    From a regional perspective Prasat Ta Muean Thom is one of a small group of ancient Hindu temples on top of the Dangrek Mountain Chain:

  Above: The ancient route, the Dharmasala Route, and the temples of the Dangrek Mountain Chain.  

     The distances from Prasat Ta Muean Thom to Prasat Bai Baek and Prasat Ta Khwai are nearly identical: 11.2 and 11.6 km. The three temples are furthermore aligned with one another! The central tower of Prasat Ta Muean Thom is only 15 m from a 22.8 km long straight line between Prasat Bai Baek and Prasat Ta Khwai.
     The three temples are furthermore aligned with Prasat Preah Vihear - some 164 km east of Prasat Bai Baek. Here the central tower of Prasat Ta Muean Thom is 30 m from from the alignment.
     The four temples are all orientated towards one of the four cardinal directions: One orientation for each temple. Listed from east: Prasat Preah Vihear (north), Prasat Ta Khwai (east), Prasat Ta Muean Thom (south), and Prasat Bai Baek (west). And all temples - except Prasat Ta Muean Thom - are constructed exactly cardinally.
     Whether these alignments are beautiful coincidences or deliberate choices will not be discussed here and now.



Further reading:
For the ancient route (Dharmasala Route, Royal Road) mentioned in the text above - see The Dharmasala Route
Other sites mentioned in the text are Prasat Preah Vihear, Vat Phou (Wat Phu), and Prasat Ta Khwai
For other sites not mentioned go to Astro-archaeology and ancient Khmer temples - index page

Courtesy to
(Carte Interactive des Sites Archologiques Khmers) for the two photos from Prasat Chan,
and to GOOGLE EARTH for making maps accessible for the public.
All other pictures are taken by the author.

''Dangerous Area'' refers to the land-mines in the area



7 September 2008 Asger Mollerup