Towering above huge, hollowed-out karst formations, these natural bridges (you don't walk across them) are the highest in the world and utterly unique; you won't see anything like them anywhere else on the planet. A wander through the mossy, green gorge floor beneath the bridges takes about two hours. A vertiginous glass elevators takes you into the gorge; once down, sedan chair carriers will try to offer you a lift and electric trams whisk the hiking-averse up the hill back to the bus terminal.