Koh Ker was part of the Khmer kingdom during the Angkor period in what is now Cambodia. For a mere two decades in the tenth century CE, the city served as royal capital, and it has long been proposed that after the royal seat moved back to Angkor, the city and its surroundings were abandoned. In this study, Hall and colleagues tested this theory by analyzing charcoal and pollen remains in sediment cores spanning several centuries in three Koh Ker localities, including the moat of the main central temple. From these data, they inferred a long history of fluctuations in...