Phimai or Vimai was the name of a large rectangular ancient Khmer city surrounded on all sides by boundary walls and moats, lying 260 kilometres northwest of Angkor.
Prasat Phimai was the Mahayana Buddhist sanctuary situated at the centre of the city. Prasat Phimai itself together with the Cultural Route and the associated temples of Phanomrung and Muangtam are among the finest Khmer monuments and constitute a testimony to the civilisation, prosperity and wealth, and the power of the Khmer Empire at its peak. From Pimai the historical route stretched out Southeast into the southern sub-region of the Khorat Plateau leading to the pass across the Phnom Dongrak mountain range on the Thai-Cambodian border. In the ancient time of the Khmer Empire, travellers and pious pilgrims taking this route, which connected Angkor to Phimai, had at their disposal rest houses spanning over the route as well as some hospitals along the route. The remains of these rest houses and hospitals mark. out Phimai's unique cultural route, covering approximately a. distance of 150 kilometres.
Prasat Phimai was originally built in the l l t century after a large part of the Buddhist Kingdom of Dhvaravadi was conquered and became the domain of the Khmer Empire. It is evident from the statuary of Phimai that it was built as a Mahayana Buddhist sanctuary. The inscriptions inside the principal tower also signify the Buddhist origin of Phimai, praising Lord Buddha and mentioning the name of King Suriyavaraman I as a Mahayana Buddhist, as well as specifying the years corresponding to the Buddhist Era of 1579 and 1589 (1036 and 1046 AD). It is significant to note that other Khmer temples belonging to the same era, such as Angkor Wat or Prasat Phanomrung, all were built as Hindu temples, the unique Buddhist sanctuary of Phimai being the single exception. Besides the Buddhist temple of Bayon in Cambodia, Phimai was duly recognised as the most important full-fledged Khmer Buddhist sanctuary by Jayavaraman VII the Great, who was a renowned fervent Buddhist.
The plan of the township was in the shape of a rectangle enclosed on all sides by moats and surrounding walls, of which traces still remain. Of the four walls, the front side of the ancient town stood, as the Temple itself, facing Southeast in the direction of Angkor. The fact that the temple of Phimai faces Southeast in the direction of Angkor instead of facing east, which is the common feature of other Khmer temples, is significant; the reason, however, is unknown. It might have been by design to give effect to the special position and importance of Phimai in its relationship to Angkor, as made evident later by the command of King Jayavaraman VII to build rest houses and hospitals on the cultural route to Phimai.
The restoration of Prasat Phimai by anastylosis from 1964 to 1969 with the technical assistance from the French Government was supervised by Prince Yachai Chitrabongse and M. Bernard Phillip Groslier, who was the director of the restoration work at Angkor. The lintels on the inside of the buildings, depicting scenes of the life of Buddha a s well as episodes from the Ramayana, are among the forest of Khmer art. A very fine sandstone statue of King Jayavarman VII in meditation was also found inside of one of the buildings.
Lying on the cultural route halfway from Prasat Tamuan on the Thai¬Cambodian border to Prasat Phimai are the two ancient Khmer temples of Phanomrung and Muangtam in close vicinity.
Prasat Phanomrung is magnificent, standing on top of an extinct, wooded volcano, and dominates the broad flat countryside marked off to the south by the Dong Rek Mountains, the thickly forested slopes of which lead away to the horizon. The construction of the temple took place in different stages, the first two brick towers dating back to the 10`h century. These were followed by the small tower, which was built in the 11 ch century, and the principal tower, built in the 12th century. Other structures including the scripture repository and the pavilion were added during the reign of Jayavarman VII. The temple was for worshiping the supreme Lord Shiva; thus Prasat Phanomrung represents His celestial abode on top of Mt. Kailasa. The monumental staircase is most impressive, with its strong moulding on the sides giving a feeling of power and mass, typical of great classical Khmer monuments. The plan. of the whole complex was designed on the basis of the axis leading from the staircase to the principal tower. The principal tower and minor buildings all have doors in symmetrical positions on all sides. The main sanctuary, in particular, has superb decoration for its strength and delicacy. All the external and internal doorways have pediments and carved lintels and the walls and pillars are covered with friezes.
An extraordinary feature of the architectural design of the sanctuary, taking advantage of its geographical location, is the straight throughway from the entrance door on the East leading to the farthest door, the 15`h door, on the western end of the structural complex. The design was made to display the spectacular sunrise of the two annual crossings of the equator by the Sun, beaming the majestic aura of the rising sun from the entrance door on the East straight through the fifteen doors to the western end of the doorway of the sanctuary. Around each time of the equinoxes, visitors to this day crowd the outside square on the west end of the Prasal Phanomrung to witness the awesome spell of the emerging sun over the horizon through the fifteen doors at the western end of the sanctuary.
Prasat Muangtam was a Hindu sanctuary built in the 11`h century on the plain 8 km southeast from Prasat Phanomrung. Although its setting is much less picturesque, its plan, importance, and the good state of preservation of its bas¬reliefs make it an outstanding ancient Khmer temple. The plan of the temple is a vast rectangle, 120 by 127 metres, enclosed with a laterite wall topped by a strong rim. At the four cardinal points are four gopuras in the middle of each side of the complex. The first courtyard is imposing in its proportions and is mostly filled with four symmetrical L-shaped ponds, at each corner of which is the figure of five-headed naga with the tails meeting at the top of the stairs on each side of the ponds leading down to the water. These ponds are separated from each other by four paths leading to the four doors of the inner courtyard which appears floating like an island. To the north of Prasat Muangtam is located the baray (known as Thale Muangtam, or Muangt:am lake), 510 by 1,090 metres, constructed as an integral part of the temple to symbolise the ocean surrounding Mt. Meru, which is the home of Hindu gods.
Associated Rest Houses and Hospitals along the Route
King Jayavaraman VII, according to the account appearing in ancient Prah Khan Stone inscriptions in Angkor, commanded that 17 rest houses be built from the capital on the route to Phimai. Eight rest houses have been found on the stretch from Phimai to the pass across the Phanom-Dongrak mountain range on Thai-Cambodian border. All rest houses are of the same size with typical identifiable structural features. The spacing of the location of rest houses varies from 10 to 26 kilometres: the different distances could have been due to the different types of terrain and the conditions of the trail encountered in one-day travel at that time. Unlike rest houses, hospitals were scattered, probably located where the communities were situated. Out of the remains of 18 hospitals found in the northeast of Thailand, six of them were on Phimai's route.