the horseshoe-shaped glass floor walkway in chongqing extends 87.5 ft from the edge of a cliff .
it is the longest cantilever bridge in the world , beating arizona 's grand canyon skywalk by 16.4 ft .
located in south-west china , the bridge has been named yuanduan , meaning ` at the end of the clouds '
the bridge can accommodate up to 200 people at once , with visits capped at 30 minutes .