Amazing transparent pathway. A glass path was built on the side of a cliff on Tianmen Mountain in Zhangjiajie National Forest Park, China. The ‘Skywalk’ is about 4700 feet (1,430m) above sea level and 200 feet (60 metres) long. The 3ft-wide, 2.5in thick glass walkway is so breathtakingly scary, makes knees go weak and is definitely not for the faint-hearted and those who suffer from vertigo. The company that built it has been unable to find anyone to keep the sidewalk clean. Until they do, daredevils are asked to wear cloth slip-ons over their shoes.