Koh Ker or Chok Gargyar, as it is known in Old Khmer inscriptions, is a 10th-century temple complex and former capital of the Khmer Empire, situated in northern Cambodia. The name of the site, Chok Gargyar, is in itself unique, as it is the only site we know of to be named in the Old Khmer language (Khmer ancient capital are usually named in Sanskrit) and referring to a natural feature, namely the tree now known as Koki or iron wood tree which can reach up to 45m and is valued for its dense wood quality that is water and termite-resistant. The densely forested site containing a total of 169 archaeological remains, including 76 temples, as well as civil structures, ponds, dykes, and ancient roads, is located centrally between three other Cambodian World Heritage Sites - Preah Vihear, Angkor, and Sambor Prei Kuk. It stands at a distance of 102 km to the north-east of Angkor Wat in Siem Reap, 126 km to the south of Preah Vihear Temple Site, and north-west to Sambor Prei Kuk Site at a distance of 171 km. Situated between the slopes of the Dangrek and Kulen mountains, Koh Ker has a landscape characterized by rolling hills of variable heights ranging from 70m to 110m, forming a gentle slope from South to North, and coinciding with the watershed of the Steung Sen River.

Koh Ker was the capital of the Khmer Empire for a brief period, between 928-941 C.E. under its founder King Jayavarman IV. As yet, the only authentic, contemporary information about the political ideology of Angkor comes from the Koh Ker inscription which establishes a clear shift of Khmer political ideology from ‘rāja’ or king, to ‘rājya’ or the kingdom and its people. In support of this new ideology, no war was waged by Jayavarman IV; his reign was the most peaceful phase of the Khmer Empire, which enabled a cultural resurgence. This time of peace allowed Jayavarman IV to carry out projects of regional, social, economic and architectural development, town planning and rural infrastructure, of which the ensemble of monuments at Koh Ker bear testimony. The art and architecture of Koh Ker was also developed to reflect and affirm the dominance and uniqueness of Jayavarman IV’s political identity, particularly with the use of a monumentality of scale in architecture, and dynamism in sculpture, both of which is unmatched in other Khmer legacies.