Reconstructing the ancient route network in the Thailand–Cambodia borders: A case study of the Angkorian Royal Road

A large number of ancient remnants from the Angkor kingdom of the 15th–19th centuries are widely observable across present day north-eastern Thailand and Cambodia. Archaeologically, these features represent the ancient communities and were possibly connected according to various socioeconomic reasons. In order to reconstruct the route of human mobility between the remains, the geographic information system (GIS)-based least cost path (LCP) analysis was employed along the Angkor–Phimai route. By recognizing the geographic parameters, the mobility of 292 moated sites was tracked to eight mountain passes that traverse the barrier of the Dângrêk Mountain Range. The LCP-derived routes revealed that the Ta Muen pass was the most suitable (shortest source-to-site distance) route for almost all moated sites. When compared with a previous interpretation of the Angkorian Royal Road route, our LCP route conforms reasonably well when overlaid with this possible Royal Road. The locations of ancient activities were also in the vicinity of the dense LCP route, and most monuments were located within a 1.5 km buffer line. This underlines that the LCP track obtained in this study is reasonable with a high reliability and is beneficial for guiding further studies to find out more about the ancient remains or archaeological evidence in this area.