The temple of heaven is not only a complex of historic religious buildings but also a very vivid park. You will find musicians, swordsmen, old people doing tai chi and lots of other stuff going on. My favorite place in Beijing.
Lijiang Oldtown was completely rebuilt in the 1990's. Still it has a very authentic historic flair. A lot of beautiful shops, restaurants, streets and other stuff to explore. When in Yunnan definitely a must visit. But beware: there will be masses of Chinese tourists ;)
The 40 km part of the Li river between Guilin and Yangshou is world famous. The mystic landscape is motive for nearly every second Chinese painting. Although we had bad weather, this trip was incredible.