Local tourists visit the Victoria Falls. The Victoria Falls constitutes one of the most spectacular natural wonders of the world. The Local people call it "Mosi-oa-Tunya" -- the smoke that thunders and the Falls are remarkable.  There is a magic about them manifested in the towering column of spray when the river is high, the thunder of the falling water, the terrifying abyss and tranquil lagoons upstream in which hippo and deadly crocodiles lurk. The Victoria falls is 1 708 meters wide, making it the largest curtain of water in the world. It drops between 90m and 107m into the Zambezi Gorge and an average of 550,000 cubic metres of water plummet over the edge every minute. Remarkably preserved in its natural state, Victoria falls inspires visitors as much today as it did David Livingstone in the 1860's. The falls and the surrounding area have been declared National Parks and a World Heritage Site, thus preserving the area from excessive commercialisation. The river's annual flood season is February to May with a peak in April. The spray from the falls typically rises to a height of over 400 metres (1,300 ft), and sometimes even twice as high, and is visible from up to 50 km (30 miles) away.  During the flood season, however, it is impossible to see the foot of the falls and most of its face, and the walks along the cliff opposite it are in a constant shower and shrouded in mist. Close to the edge of the cliff, spray shoots upward like inverted rain, especially at Zambia's Knife-Edge Bridge. As the dry season takes effect, the islets on the crest become wider and more numerous, and in September to January up to half of the rocky face of the falls may become dry and the bottom of the First Gorge can be seen along most of its length. The minimum flow, which occurs in November, is around a tenth of the April figure.