most of the sacred mountains in China are understandably enough very crowded in the summertime. they are an ideal refuge away from the heat and congestion of the central plains.

However it should still be possible to find some solace away from the crowds, especially if you venture into some of the more far away places like for example Wutaishan.
Wutaishan is a holy buddhist mountain in Shanxi province in the north of China. It is quite easy to get to with a couple of direct busses a day from Beijing taking around 5 hours.

Here you can trek in the alpine wilderness and it is possible to spend the night in one of the numerous temples on the mountain tops. Remember if you stay in a temple to not bring any meat with you since it is strictly forbidden to eat meat in Buddhist monasteries.

lets make ourself clear: nothing in china is sacred