Chengjiang in Yunnan is one of the most important pre-Cambrian explosion fossil sites on earth. The museum is excellent. If you ever get to visit Yunnan, don't miss it. They rebuilt it about 5 years ago and it is even better than the last one, featuring animatronics and numerous fossil displays. Also, the lake nearby is the second deepest in China (after the one on the North Korean border, I believe) and is thus still pretty clean. I used to sail on the lake, at 2200m altitude and 20km long, it puts the Swiss to shame. A pleasant high altitude environment to observe and ponder the passage of time. Great banquets. Mushroom season is circa august, and there's a cute French colonial era railway running down the valley to the east.