Preah Ko is a profoundly significant temple that often gets overshadowed by the grandeur of Angkor Wat and Bayon. Preah Ko, which translates to “Sacred Bull,” was the very first temple built in the ancient city of Hariharalaya, located in present-day Roluos, 15 kilometres southeast of Siem Reap. This temple predates Angkor Wat by over two centuries and is key to understanding the architectural and spiritual foundation of the Khmer empire.