The Blyde River Canyon, officially the Motlatse Canyon is a significant natural feature of South Africa, located in Mpumalanga, and forming the northern part of the Drakensberg escarpment. Located in the Blyde River Canyon Nature Reserve, it is 25 kilometres (16 mi) in length and is, on average, around 750 metres (2,461 ft) deep. The Blyderivierpoort Dam, when full, is at an altitude of 665 metres (2,182 ft). The canyon consists mostly of red sandstone. The highest point of the canyon, Mariepskop, is 1,944 metres (6,378 ft) above sea level, whilst its lowest point where the river leaves the canyon is slightly less than 561 metres (1,841 ft) above sea level. This means that by some measure the canyon is 1,383 metres (4,537 ft) deep.

While it is difficult to compare canyons world-wide, Blyde River Canyon is one of the largest canyons on Earth, and it may be the largest 'green canyon' due to its lush subtropical foliage. It has some of the deepest precipitous cliffs of any canyon on the planet. It is the second-largest canyon in Africa, after the Fish River Canyon, and is known as one of the great wonders of nature on the continent.

Possibly the best view in the whole of the Blyde River Canyon is of the "Three Rondavels", huge, round rocks, thought to be reminiscent of the houses or huts of the indigenous people, known as rondavels.

More Info: en.wikipedia.org