We were meant to go to the Danxia Rainbow mountains, but we got to Zhangye too late so ended up here. It is a beautiful and peaceful temple complex that has a fascinating history.
There is English explaining what each of the buildings are, but that's about it I'm afraid. If you can speak Chinese then the guides are quite good. They tell you the interesting legends surrounding the temple, including how the giant sleeping buddha survived destruction several times at the hands of the Russians and the cultural revolutionaries. I agree with @tsandweg that it would be worth looking up some history before you go if you don't speak Chinese.
I highly recommend taking the time to see this place if you are in Zhangye. In fact I'd even suggest making the stop for a day if traveling by train between Lanzhou and Jiayuguan.
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