For a few short decades in the tenth century, the capital of the Khmer empire was not at Angkor but here, deep in the forest of northern Cambodia. King Jayavarman IV established his court at Koh Ker, then called Lingapura, and in less than twenty years his builders raised dozens of temples across a wide area, before the capital returned to Angkor. The jungle took the city back. Today Koh Ker is a scatter of brick and sandstone sanctuaries among the trees, and in 2023 it was added to the UNESCO World Heritage list.
The centrepiece is Prasat Thom, a seven-tiered stepped pyramid that rises steeply above the surrounding forest. It looks more like a Mesoamerican temple than anything at Angkor, and it is an astonishing sight when you emerge from the trees. Around it lie dozens of smaller temples, some with enormous lingas, others with doorways framed by carved sandstone, many half-collapsed and overgrown with roots and moss. Compared with Angkor, the crowds here are tiny, and you can often wander alone among the ruins, listening to birds and insects.
Cambodia's recent history is never far away. The area was heavily mined during the decades of conflict, and although clearance teams have made the main sites safe, it is essential to stay on marked paths and not to wander into the forest. Local guides know the ground and are worth hiring.
The ride from Siem Reap takes a couple of hours or more, passing the huge, ruined temple of Beng Mealea, which is worth a stop in its own right: a sprawling complex swallowed by the forest, with walkways over the collapsed stones. The roads are now paved for most of the way, with long straights through rice paddies and villages, but watch for potholes, cattle, dogs, scooters and trucks. Further north, the road continues towards Preah Vihear, a temple perched on a cliff at the Thai border, with an extraordinary view over the plain.
Fuel is sold in villages along the way, sometimes from glass bottles at roadside stalls, but fill up in Siem Reap or larger towns when you can. Bring water, a hat and sun protection; the heat can be intense, especially from March to May. The rainy season, from June to October, makes the forest lush but can turn dirt tracks to mud. Cambodia drives on the right.