Pailin is a province located in western Cambodia at the northern edge of the Cardamom Mountains near the border with Thailand. It is surrounded by Battambang province and was officially established as a separate administrative division after being carved out of Battambang following the 1996 surrender of the Ieng Sary faction of the Khmer Rouge.
The region is historically significant for having served as a long-standing stronghold of the Khmer Rouge, remaining under their control well after their defeat in 1979. From 1994 to 1998, Pailin served as the capital of the Provisional Government of National Union and National Salvation of Cambodia. Within the country, the province is primarily recognized for its natural resources, specifically timber and precious gems.