Aerial photo taken on May 15, 2019 shows a railway construction site with China Railway Tunnel Group in the Altun Mountains, northwest China's Xinjiang Uygur Autonomous Region. There is a nature reserve covering 45,000 square kilometers of the Atlun Mountains, which are home to many wild lives. A lot of effort has gone into environmental protection in Altun over the past few decades. Ecosystems have regenerated on the nature reserve since it was set up in the 1980s to keep poaching, illegal trespassing and mining at bay. Some 400 km away from the uninhabited reserve, 3,000 meters above sea level, the workers are building a railway connecting cities in the northwestern provinces of Xinjiang and Qinghai. They get along quite well with unlikely neighbors. (Xinhua/Ding Lei)