Tourists pose for photos on the 100-meter-long and 1.6-meter-wide glass bridge built on the cliff of the Tianmen mountains in Zhangjiajie scenic area, Hunan province, on August 1, 2016, as the third glass bridge in the scenic spot opens to the public on Monday. Walking on the high-altitude glass bridge, people can enjoy the dizzying view of the "heaven-linking Avenue", the twisting mountain road from the foot of the mountains to the Tianmen Cave. [Photo/VCG]

A tourist takes selfie on the 100-meter-long and 1.6-meter-wide glass bridge built on the cliff of the Tianmen mountains in Zhangjiajie scenic area, Hunan province, on August 1, 2016, as the third glass bridge in the Tianmen scenic spot opens to the public. [Photo/VCG]

Visitors walk on the narrow glass bridge built on the cliff of the Tianmen mountains in Zhangjiajie scenic area, Hunan province, on August 1, 2016, as the third glass bridge in the Tianmen scenic spot opens to the public. [Photo/VCG]

Tourists walk on the newly opened glass bridge, which offers visitos the amazing view of the "heaven-linking Avenue", the twisting mountain road from the foot of the Tianmen mountains to the Tianmen Cave, in Zhangjiajie scenic area in Hunan province on August 1, 2016. [Photo/VCG]

A tourist takes selfie on the 100-meter-long and 1.6-meter-wide glass bridge built on the cliff of the Tianmen mountains in Zhangjiajie scenic area, Hunan province, on August 1, 2016, as the third glass bridge in the Tianmen scenic spot opens to the public. [Photo/VCG]

Visitors walk on the narrow glass bridge built on the cliff of the Tianmen mountains in Zhangjiajie scenic area, Hunan province, on August 1, 2016, as the third glass bridge in the Tianmen scenic spot opens to the public. [Photo/VCG]

Tourists walk on the newly opened glass bridge, which offers visitos the dizzying view of the "heaven-linking Avenue", the twisting mountain road from the foot of the Tianmen mountains to the Tianmen Cave, in Zhangjiajie scenic area in Hunan province on August 1, 2016. [Photo/VCG]