Vast, remote and hardly touched by tourism, Preah Vihear Province (ខេត្តព្រះវិហារ) is home to three of Cambodia's most impressive Angkorian legacies. Stunningly perched on a promontory high in the Dangrek Mountains, Prasat Preah Vihear became Cambodia's second Unesco World Heritage Site in 2008, sparking an armed stand-off with Thailand. Further south are the lonely, jungle-engulfed temples of Preah Khan – totally isolated and imbued with secret-world atmosphere. More accessible is 10th-century capital Koh Ker, which is day-tripping distance from Siem Reap.
Preah Vihear Province is genuine ‘outback’ Cambodia and remains desperately poor – partly because many areas were under Khmer Rouge control until 1998, and partly because until recently its transport infrastructure was in a catastrophic state. The needs of the Cambodian army in its confrontation with Thailand have expedited dramatic road upgrades in the province, making travel more straightforward, although public transport is still in short supply on some routes.