Prasat Tam Moat is the water-filled moat encircling Prasat Tam, one of the temple complexes at Koh Ker — a remote jungle city in northern Cambodia that served as the capital of the Khmer Empire for roughly two decades in the 10th century. The moat was an integral component of Koh Ker's water-management system, a remarkable feat of engineering in a region that lacked a substantial natural water source. Today, the murky water conceals what researchers believe may be a significant cache of carved stonework, reportedly toppled into the moat by Khmer Rouge soldiers who intended to recover the pieces for smuggling at a later date. Fragments of the famously dynamited Dancing Shiva statue are also believed to rest somewhere on the moat's floor, making the site as much a crime scene as an archaeological dig. Gates investigated the submerged moat during a broader episode exploring the looted and damaged heritage of Koh Ker, deploying underwater technology to peer below the surface for the first time.
King Jayavarman IV relocates the Khmer capital from Angkor to Koh Ker, ordering construction of palaces, temples, and water infrastructure including the moats of the Prasat Tam complex
Koh Ker is abandoned as the Khmer capital under Jayavarman IV's successor; the city is gradually reclaimed by jungle
Khmer Rouge soldiers and subsequent looters reportedly topple statues into the Prasat Tam moat, intending to smuggle them out; the iconic Dancing Shiva is dynamited and its fragments believed to fall into the water
Josh Gates investigates the moat in Expedition Unknown S12E08, deploying a VideoRay Defender ROV with multibeam sonar to scan the submerged bottom
The moat at Prasat Tam sits within Koh Ker, a city that the Khmer king Jayavarman IV built from scratch in a remote jungle location around the early 10th century CE. As Gates learns on camera from Cambodian archaeologist Phin Phakdey during the same episode, the Khmer Empire ruled over much of Southeast Asia for roughly 600 years, making it one of the most powerful civilizations of its era — yet Koh Ker served as its capital for only about 20 years before being mysteriously abandoned. The water-management engineering required to sustain a city in this jungle without a major river is itself considered a remarkable achievement by researchers.
The moat's contents represent a layered archaeological tragedy. According to accounts from former looters cited in the episode's framing, Khmer Rouge soldiers deliberately toppled statues into the water during the conflict era, intending to retrieve them later for the black market. The famous Dancing Shiva — a masterpiece of Khmer sculpture — was reportedly dynamited, and its fragments are believed to have ended up submerged. The full extent of what lies on the moat floor remains, as of the episode's airing, genuinely unknown.
The snake-skin patterned sandstone fragment recovered during the ROV survey is described by the team as potentially consistent with a Naga serpent railing. Naga imagery — the multi-headed serpent deity — is a recurring motif throughout Khmer temple architecture, frequently used as decorative railings on causeways and moat bridges. Whether the recovered fragments can be definitively matched to a specific structure at Prasat Tam would require further specialist analysis beyond what the episode documents.
Gates' investigation is best understood as an initial reconnaissance rather than a comprehensive excavation. The use of multibeam sonar and ROV technology in a context like this is genuinely useful for mapping the moat bottom and flagging areas of interest — but the episode is careful not to claim that the Dancing Shiva or complete statues were located. The episode contributes a documented underwater survey and recovered fragments to the public record of Koh Ker's ongoing archaeological story, at a site where systematic underwater archaeology has historically been limited.
Koh Ker served as the capital of the Khmer Empire for only approximately 20 years before being abandoned — a brief but architecturally prolific reign under King Jayavarman IV and his son Harshavarman.
The Hindu god Varuna, whose carvings Gates examines at nearby Prasat Krachap, was both the god of the west and the god of water — a particularly significant deity for a city that lacked a strong natural water source.
According to accounts cited in the episode, Khmer Rouge soldiers toppled statues into Prasat Tam's moat with the intent of retrieving them later for smuggling — a fate that reportedly befell numerous Khmer artifacts during the conflict era.
The Naga — a multi-headed serpent deity — is among the most iconic motifs in Khmer temple architecture, typically appearing as decorative railings on causeways; a sandstone fragment with snake-skin patterning recovered from the moat is believed to be consistent with just such a railing.
Koh Ker is generally accessible to visitors as part of Cambodia's broader Angkor Archaeological Park region, though it lies roughly 80 miles from Siem Reap and requires dedicated transport. The temple complexes, including Prasat Tam, are open to visitors, though conditions at and around the moat itself may be subject to ongoing archaeological work or restricted access — check current advisories from Cambodia's APSARA Authority or local guides before visiting.
Siem Reap, Cambodia — approximately 80 miles (roughly 130 km) southwest, typically a 2–3 hour drive depending on road conditions.
The dry season, roughly November through April, is generally considered the most practical time to visit Koh Ker, with lower humidity and more manageable road conditions. The wet season brings lush greenery but can make jungle tracks to remote temples difficult to navigate.
Cambodia National Museum, Phnom Penh
The Cambodia National Museum in Phnom Penh holds significant collections of Khmer sculpture and artifacts, including pieces recovered from sites like Koh Ker, making it a natural complement to understanding what was looted from and around Prasat Tam.
Guatemala Snake King Archaeological Sites
The Guatemala Snake King Archaeological Sites share a thematic connection — Gates investigating a powerful and mysterious ancient civilization whose jungle capital was abruptly abandoned, with significant archaeological work still ongoing.
Sky Caves of Nepal
Like Prasat Tam, the Sky Caves of Nepal represent a Gates investigation using specialized technology (ROV and sonar in Cambodia; high-altitude climbing in Nepal) to access hidden or hard-to-reach archaeological contexts where artifacts may have been deliberately concealed.