Siem Reap Urban Adventures offers sightseeing tours in Siem Reap that open the gateway to the amazing UNESCO World Heritage archaelogical site of Angkor. These 1000 year old ruins are the remains of the highly developed Khmer empire. Nestled between rice paddies and the Siem Reap River, and not far from the Tonle Sap Lake biosphere reserve, the township is a great base from which to explore.