Photo taken on Jan 18, 2016 shows the glass bridge across the Zhangjiajie Grand Canyon under construction in Zhangjiajie, central China's Hunan Province, Jan 18, 2016. The bridge is 430 meters long, six meters wide and 300 meters above the valley. It is capable of holding 800 people at once and is expected to be opened to tourists in the first half of this year. [Photo/Xinhua]