Alligator Rivers is the name of an area in an Arnhem Land region of the Northern Territory of Australia, containing three rivers, the East, West, and South Alligator Rivers. It is regarded as one of the richest biological regions in Australia, with part of the region in the Kakadu National Park. It is an Important Bird Area (IBA), lying to the east of the Adelaide and Mary River Floodplains IBA. It also contains mineral deposits, especially uranium, and the Ranger Uranium Mine is located there. The area is also rich in Australian Aboriginal art, with 1500 sites. The Kakadu National Park is one of the few World Heritage sites on the list because of both its natural and human heritage values. They were explored by Lieutenant Phillip Parker King in 1820, who named them in the mistaken belief that the crocodiles in the estuaries were alligators. Rivers The East Alligator River is about long. After rising in the northern part of the Arnhem Land Plateau, it flows with tributary streams towards the northwest, through canyons towards the Van Diemen Gulf, which it meets at Point Farewell. The river has a total catchment area of and has many tributaries, including Magela Creek, Tin Camp Creek, and Cooper Creek. The catchment is surrounded by the South Alligator River catchment to the west and Goomadeer and Liverpool River catchments to the east and the Daly River catchment to the south. The river has an annual average discharge of per year. The South Alligator River is also about long. It rises north of Mount Stow, on the Arnhem Land Plateau. It flows northwesterly in a valley containing a number of disused uranium mines developed between 1955 and 1965. It also flows out into the Van Diemen Gulf of the Timor Sea. The catchment area occupies an area of and has the East Alligator River catchment to the east, the Wildman and Mary River catchments to the west, and the Daly River catchment to the south. The West Alligator River rises in the lowlands and is . The Wildman River also flows in the region. The river system has a number of spectacular waterfalls, including the Jim Jim Falls on Jim Jim Creek and the Twin Falls on Twin Falls Creek. The rivers have created the alluvial plains, including the mangrove swamps, in the past 20,000 years. Climate Like much of northern Australia, the Alligator