Down near the border of China and Vietnam are the Detain Falls. They are the largest transcountry falls is Asia i was told. Anyway they are spectacular and worth the trip if you want some good photo's, the rafts take you up close and personal so make sure you have a waterproof camera. About a 3 - 4 hr bus ride from Nanning, next time i think i'd like to stay at a hotel there as the area and reserve is quite large and the short time available didn't leave a lot of time to explore all of it.