Zimbabwe: steep mountain ranges cut Zimbabwe off from the eastern plains that border the India Ocean. The High Veld is a central ridge forming the country's watershed, with stream flowing southeast to the Limpopo and Sabi rivers and northwest into the Zambezi. Zimbabwe boasts the majestic Victoria Falls, magnificent wildlife preserves and the medieval ruins of Great Zimbabwe, as well as the bustling city of Harare. Lake Kariba is an artificial inland sea, Africa's third largest dam, that covers 282km² of the Zambezi Valley. It is now a very popular resort lake with an airport, harbour, lakeside hotels and lodges, huge houseboats, marinas, water-sports and fishing.