The Ancient Khmer Highway was a roadway going northwest between Angkor and Phimai, now in Thailand. It has a length of 225 kilometers. While it was not the only such road built by the Khmer, it was the most important one.

Most of the road is overgrown by the jungle already, which makes it only visible on aerial photographs. Only a few of the rest house chapels or hospital chapels are still found today - only the chapels remain as they were the only buildings built of sandstone or laterite, all the wooden parts rotted away long ago. The only part of the road which is still driveable is at the entrance to the city Phimai (state route 2163).

The road has been proven to exist in the 12th and 13th century, but it is quite certain that it existed earlier. Most of the buildings along the road date from the reign of King Jayavarman VII.

The road uses the Ta Muen Thom pass over the Dongrek mountain range. The first major stop on the road was the Phanom Rung temple.

References

• Michael Freeman, A Guide to Khmer Temples in Thailand and Laos, ISBN 0834804506