
Little do most people realise when they’re whizzing along in their bright blue bus that many important routes in Thailand’s impressive 21st-century road network follow the traces of, and are built over the top of, ancient roads dating from the Angkor period. (As for example with England’s road infrastructure and the Romans.)
The extensive Angkor road network covered not only Cambodia but large areas of what is now Vietnam and Thailand. Roads spider-webbed out from the capital at Angkor Tom to the distant reaches of the empire facilitating trade and movement of goods and loot and helping the great empire-building kings such as Suryavarman I & II and Jayavarman VII to rapidly move their huge armies from one trouble spot to another.
It’s a safe assumption that the closer the roads to the capital the better they were with raised, laterite surfaced all-weather roads, an extensive bridge system and Jayarvarman’s famous ‘rest houses’ along the way. Whilst routes to remote outposts may have been fairly basic they also followed logical courses and the tracks and roads that extended across much of central Thailand have been upgraded and upgraded ever since until now we have major 6 lane highways covering the exact paths of 12 or 13th-century tracks and roads.
Since in many areas of Cambodia little upgrading has been undertaken since the 13th century it’s a lot easier to see the more obvious traces of many old roads. For example, the N6 which in part traces the old route from Bhavapura/Ishanapura, (Sambor Prei Kok) to Angkor still used the impressive Jayavarman VII period bridge at Kompong Kdei up to only a few years ago and many preserved minor bridges can be seen along the road side.

Important Angkor roads in Cambodia include the route south from modern Phnom Penh linking up Ta Prom Tonle Bati, Phnom Chisor and Angkor Borei – now the National 2, the aforementioned Sambor Prei Kok to Angkor route, the famous Angkor to Beng Melea route from where a fork leads to Koh Ker and another east to Preah Khan (the former has been upgraded in parts the latter untouched since), an east by north east route linking up with the vast Banteay Chmar site and the important northern route heading to Pimai by way of Ta Muan, Phnom Rung etc. (Many traces of the latter 2 can still be seen today).

Just down the way from Ta Muan Tom is one of Jayavarman’s way stations/rest houses, (a kind of Khmer caravanserai), of which he is said to have built 121 at strategic points along the most important of the ‘Royal Roads’.
The ‘Thai’ section of the Angkor to Pimai road which is thought to have begun at the Dandrek pass at Ta Muan before heading west to the city of Muan Tam and the major pilgrimage site of Phnom Rung where it turned north-west to Pimai. The provincial route 224 is a good bet for the Ta Muan – Phnom Rung section and indeed several minor Khmer ruins can be found close to this road but apart from the 2 ‘ends’ – Phnom Rung to Nang Rong and Pimai to Hin Dat – the section from Phnom Rung to Pimai is difficult to ascertain. As far as we know this important Angkor road hasn’t been much researched to date but traces must exist. (It would be very interesting to check this out further!)

Another route which must have been of vital importance – connecting the significant Khmer towns of Lopburi and central Thailand to Angkor – is the trail that went due west from modern Aranyaprathet via Prachinburi (with its minor Khmer ruins), to the old Mon settlement of Ayuthaya. The modern national #33; Aran’ – Sa Kaew, Prachin’, Nakorn Nayok – Ayuthaya seems to follow the precise route. There were numerous old Mon cities in the lower Chao Phraya region which fell under Khmer rule from the reign of Suryavarman I and a network of roads would have spread out from Ayuthaya including the one to Lopburi (Lavo or Lavodayapura), which now lies presumably hidden underneath the modern 3196.
In a westwards direction the 329 covers the road to the old city of Suphanburi (Svarnapura) before becoming the 321 and 324 to Kanchanaburi and the Khmer frontier post of Muang Singh or Jayasimhapuri. From Muang Singh, trade routes would have proceeded north-west up the Kwai Valley as well as south to Ratchaburi, (Jayarajapura) and the settlement at Petchaburi.

Further afield, the authors Tamura and Ishiwiza in ‘Along The Royal Roads to Angkor‘, (Weatherhill 2005), identify a road heading north out of the regional capital Pimai to modern-day Vientiane. According to their map, the long ancient route corresponds precisely to the modern, busy 4 lane highway #2 from Khorat to Khon Kaen to Udon to Vientiane.
Thailand’s principle north-south highway #1 also gets a mention with the stretch between Singburi, Nakorn Sawan and Kamphaeng Phet seemingly following the route of the old Angkor Lopburi to Sukhothai route. (The path of a suggested direct route from Pimai to Sukhothai however is not immediately obvious from a current map of Thailand.)
Traces of more minor trails may still exist around other significant regional settlements in the Thai party of the Angkor Empire; – perhaps, for example, heading towards the important northern city of Haripunchai, (modern Lamphun), accessing the old port town of Chantaburi or linking up some of the smaller Khmer sites of N. E. Thailand such as the former garrison town of Surin, the temple at Sikhoraphum, the pilgrimage centre of Preah Vihear and so on.

Remains in the heavily populated and intensively cultivated lower Chao Phraya region are going to be hard to find these days but check out those odd laterite blocks on the raised trail through the paddy-fields behind the wife’s home village in Ubon and you may just have hit upon a 12t- century ‘Royal Road’ to Angkor!
Cheers!