A group of brave tourists learnt the meaning of vertigo the hard way as they bacame the first visitors to cross a new 590 foot high glass-bottomed suspension bridge in China.This special structure,the first of its kind in the world,is situated in the province of Hunan.Images have emerged online showing the visitors gripped with fear and frozen in awe while standing on the see-through walkway.One female tourist is seen clutching so the handrail tightly and had to be dragged along by her friend.