If you want to travel from Xi'an to Chengdu by train, it will take about 16 hours. But from November, 2017, the new Xi'an-Chengdu high-speed railway will shorten this travel time to three hours.

    The 643-kilometer line is China's first high-speed railway to run through the Qinling Mountains, which form a natural boundary（分界线）between China's north and south. With a speed of 250 km an hour, it's also the first mountain-heavy train line to provide a 4G network.

Along the way, the train passes through two areas for important wild animals — one for pandas and the other for crested ibises（朱鹮）.

    In order to influence（影响）animals less, workers have built the railway to be environmentally friendly, China Daily reported.

    As of September, there were 345 wild pandas living in the Qinling Mountains. Now China has 1,864 wild pandas, according to the Xinhua News Agency.

    To avoid disturbing（打扰）the pandas, the railway run through tunnels（隧道）within the area. Protective shields（防护屏）are placed near the entrance of each tunnel to stop animals from going in.

    To protect the thousands of crested ibises that fly near one part of the railway, protective nets have been set up along the tracks to make sure the birds will not fly into a train.

    The nets are about 32 km long and 4 meters high. Experts tested different shapes and materials for building the nets before making their final choice.