Mati Si is one of the places you can visit while in Zhangye, other than the more famous Rainbow Mountains. This destination is a good day trip from the city; there are ancient structures and beautiful views.
The Rainbow Mountains in Zhangye was atop my list of places to visit during this trip to China. When I got to the nearest town, I was already excited for the sunset trip the following day. Guides online and print said the best time to visit was sunset, and true enough, it didn't disappoint.
I didn't know much about this place until the bus I was on (I was going elsewhere) passed by this beautiful park. I asked the person behind me what its name was, and made sure to return to it the following day.