High-speed trains linking Xi'an and Chongqing begin operation

The bullet train D4251 to Chengdu, capital of southwest China's Sichuan Province, leaves the Xi'anbei Railway Station in Xi'an, capital of northwest China's Shaanxi Province, Dec. 6, 2017. The Xi'an-Chengdu high-speed rail line went into operation Wednesday, slashing the travel time between the two cities from about 11 hours to just 4. The 658-kilometer new line is China's first rail route running through the Qinling Mountains, the natural boundary between north and south China. (Xinhua/Wang Shutian)