Chinese builders have upped the stakes by building the world’s longest and highest glass bottom bridge. It is set to open in a few months above the Zhangjiajie Grand Canyon, though the official opening date has been pushed back to January 2017.

Spanning two cliffs high above the majestic natural feature, the new bridge will stretch 429 metres long, measures 6 metres wide, and tower 300 metres above the ground.

The Zhangjiajie Grand Canyon in Hunan’s Zhangjiajie National Park is believed to have inspired visuals for James Cameron's epic 2009 film "Avatar,” with its foggy sweeping vistas and craggy green peaks.

The chief architect behind the project is Israeli Haim Dotan, who designed the Expo 2010 Shanghai's Israel Pavilion. China Construction Group began working on the bridge last summer. The walkway is being constructed with 1.9-inch-thick glass panels and features several glass observatories at various sections. It will also allow daring tourists bungee jumping opportunities. 

The project was originally slated to open in January but has since faced multiple construction delays due to bad weather and local government interference. 

By comparison, the Grand Canyon Skywalk in Arizona is just 21 metres long and hovers about 218 metres above the canyon floor. Canada's Glacier Skywalk in Alberta, which opened last year, extends 35 metres from the cliff and is just under 300 metres tall.

Zhangjiajie bridge officials have said that only 800 guests will be allowed on the walkway at a time to prevent exerting too much pressure on the glass and underlying structure.