Based on the author"s doctoral dissertation, this study reports on research carried out alongside the Royal University of Fine Art-University of Hawai"i project, on the prehistoric circular earthworks of Cambodia. Dega introduces his research aims and methodology before describing the sites and earthworks, their chronology, lithic and ceramic finds and the distribution of sites, their function and significance. The sites appear to represent a unique cultural tradition that existed c.1300-300 BC.