Victoria Falls, waterfall, c.1 mi (1.6 km) wide with a maximum drop of 420 ft (128 m), in the Zambezi River, S central Africa, on the Zambia-Zimbabwe border. The falls are formed as the Zambezi plummets into a narrow chasm (c.400 ft/120 m wide) carved by its waters along a fracture zone in the earth's crust. Numerous islets at the crest of the falls divide the water to form a series of falls. The thick mist and loud roar produced there are perceptible from a distance of about 25 mi (40 km). The Boiling Pot, the beginning of a winding gorge (c.50 mi/80 km long) through which the river flows below the falls, is spanned by a 650 ft (198 m) long bridge that is 310 ft (94 m) above the river. The gorge is now partially submerged as a result of the construction of the Kariba Dam. David Livingstone, the British explorer, visited the falls in 1855 and named them for Queen Victoria. The falls are part of two national parks and draw many tourists to the area.