For my part, it is one of the most beautiful regions of interior Cambodia. You can explore some tracks around the n64, but be careful and stay on farm roads. After booking a hotel in the town of Preah Vihear, stop for a hike to the tang You waterfalls (be careful, there are road checks on the N62) but above all, book a day to go around Kaoh Ker. You can ride on tracks that link dozens of temples to a pyramid that overlooks the jungle.