Visitors experience a suspension steel bridge up in the air at an outdoor sports park in Cili county, Zhangjiajie city of central China’s Hunan province, Nov. 28, 2018. [Photo/Xinhua]

Aerial photo taken on Nov. 28, 2018 shows visitors experiencing climbing at an outdoor sports park in Cili county, Zhangjiajie city of central China’s Hunan province.[Photo/Xinhua]

Visitors experience climbing at an outdoor sports park in Cili county, Zhangjiajie city of central China’s Hunan province, Nov 28, 2018. [Photo/Xinhua]