Masjid in Xinjiang, China. This village outside of Turpan is called Tuyok Valley (Chinese: 吐峪沟 Tŭyùgōu) and is not on most itineraries. I visited-it's beautiful. More info at Far West China - http://www.farwestchina.com/2013/04/traveling-to-turpans-tuyoq-valley.html
Urumqi, Northwestern China. While China remains popular with tourists the Western region of the world's most populous country is rarely traveled. Despite a brilliant train network which stretches across the country, places like Urumqi, with its Islamic influence remain unknown. The same can be said for a Chinese entry in to Tibet (Versus the popular Nepal-side entry).