Blyde River Canyon, 25 kilometres (16 mi) in length and is, on average, around 750 metres (2,461 ft) deep. The highest point of the canyon, Mariepskop, is 1,944 metres (6,378 ft) above sea level, 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. Thus 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. The canyon has an abundant diversity of wildlife including hippos and crocodiles, and every primate species that may be seen in South Africa. The diversity of birdlife is similarly high.