By far the best trip I went on, was to Tongling Grand Canyon, Jingxi County, Guangxi. It is 30 kms further north than Detian waterfalls, but you could visit both scenic spots in the same trip. Detian is a very poor relation to what you will see at Tongling.
We descended 200 metres down Tongling Canyon, so you need to be fit, the way out involves climbing 6 or 700 steps. A waterfall of great height pours over a cliff and disappears down the canyon. Tongling Grand Canyon is more than 10 kms long. We walked over a hill and down into the next valley between the karst limestone hills, similar to the ones at Guilin and occurring all across Guangxi. At the bottom we boarded inflatable dinghies and drifted downstream through cave systems before emerging at the road, where our coach was waiting. It was spectacular and the only access route between the hills was via the river or hacking your way through the tropical forests. It is remote and unspoilt and many rare plants are found there. I really felt I had been back to nature whereas Guilin and Yangshuo are just overrun with tourists, thieves and hawkers.