A well-preserved rainforest with an Endangered Primates Rescue Centre near the entrance. You can only visit the centre with a park guide, which costs an extra 20,000 dong per person and doesn't take long. There are about 150 primates here being prepared for release back in the wild. Most are from other parts of Vietnam and any releases will be where they originally came from. There is also a botanical garden near the entrance. From the entrance you can drive, motorbike or cycle a further 20 km along a densely forested paved road, from which several bypaths lead you through the jungle to prehistoric trees and caves. Cycling is probably the most rewarding way to travel this 20 km of often steeply inclined paved road and mountain bikes can be hired at the park entrance. The road ends at the park centre (Bong), from where there are several forest walks. The park centre has a restaurant and a place to buy snacks. The best chance to see any animals here is at night. Guided night tours for overnight stayers are available. There are other points of interest along the narrow 20 km road such as a cave, ancient trees, and walking trails. One of the amazing things about this drive is the thousands of colourful butterflies filling the roadway. Peak time for butterflies apparently is Apr-May, but in later months there may still be many to be seen. It is especially enjoyable to touch the thousand-year-old cho xanh (parashrea stellata) and sau (dracontomelum duperranum or dancorra edulis) trees, 50-70 m high. The park is also perfect for seeing birds, butterflies, and orchids. They are more concentrated than in a typical butterfly farm enclosure. A limited amount of overnight accommodation is available in either a detached bungalow or a stilt house.