The Vikos Gorge, with a length of 32 km (20 mi), walls that range from 120–1,350 m (390–4,400 ft) deep, and a width ranging from 2,500 m (8,202 ft) to just a few meters at its narrowest part, is listed by the Guinness Book of Records as the deepest canyon in the world in proportion to its width, though some gorge ...