Israeli architect Haim Dotan designed the world’s highest and longest transparent glass bridge spanning China’s Zhangjiajie Grand Canyon, one of the most popular scenic spots in China.  It is 430m long and 300m high and took only 18 months to complete at a cost of approximately £48 million.

http://www.dailymail.co.uk/news/article-3598945/Is-world-s-terrifying-attraction-China-s-2-6-million-glass-bottomed-bridge-built-980ft-valley-bungee-platform-SWING.html

https://www.youtube.com/watch?v=cFoWV8malws