Never underestimate the power of moving water -especially over millions of years. The canyons created by rivers are sculptural wonders found all over the globe. You are probably familiar with the Grand Canyon in the U.S. but do you know about Blyde River Canyon in South Africa? Unlike the Arizona canyon, this one (shown here) features tropical flora and fauna along its average depth of 2,500 feet. And the view is spectacular! See the other canyons at Environmental Graffiti. Link
(Image credit: Dr. Thomas Wagner)