<P> The Yarlung Tsangpo Grand Canyon (or Tsangpo Canyon), along the Yarlung Tsangpo River in Tibet, is regarded by some as the deepest canyon in the world at 5,500 m (18,000 ft). It is slightly longer than the Grand Canyon in the United States . Others consider the Kali Gandaki Gorge in midwest Nepal to be the deepest canyon, with a 6400 m (21,000 ft) difference between the level of the river and the peaks surrounding it . </P> <P> Vying for deepest canyon in the Americas are the Cotahuasi Canyon and Colca Canyon, in southern Peru . Both have been measured at over 3500 m (12,000 ft) deep . </P> <P> The Grand Canyon of northern Arizona in the United States, with an average depth of 1,600 m (one mile) and a volume of 4.17 trillion cubic metres, is one of the world's largest canyons . It was among the 28 finalists of the New7Wonders of Nature worldwide poll . (Some referred to it as one of the 7 natural wonders of the world .) Copper Canyon in Chihuahua, Mexico is deeper and longer than the Grand Canyon . </P> <P> The largest canyon in Africa is the Fish River Canyon in Namibia . </P>

Is the grand canyon the biggest canyon in the world