With its forest of quartz sandstone pillars wrapped in clouds and mist, China’s Zhangjiajie, in central Hunan province, is famously the inspiration for the floating “Hallelujah” mountains in Hollywood blockbuster Avatar.  

I am taking in the views along the Zhangjiajie Glass Bridge, overlooking a canyon, when several of my tour mates start to gather at one spot, putting down their bags.