cataract on the Potaro River, west-central Guyana. After a sheer drop of 741 feet (226 m) over the edge of a sandstone plateau, the falls have eroded a gorge, 5 miles (8 km) long, that descends another 81 feet (25 m). The falls are 300 to 350 feet (90 to 105 m) wide at the top and are the central feature of the Kaieteur National Park (established 1930). Tourists usually visit the site by chartered aircraft from Georgetown, but a road and river expedition is also possible. The falls were sighted by C. Barrington Brown, a British geologist, in 1870.