Zimbabwe sits in southern Africa between the Zambezi and Limpopo rivers. On April 18, 1980, it became an independent country. Before that, a small group of white settlers controlled the government. The majority Black population fought for years to gain equal rights and self-rule. The country's name comes from Great Zimbabwe, a stone city built between the 1100s and 1400s. The ruins include massive walls made from granite blocks fitted together without any mortar. The tallest wall stands over thirty feet high. Historians believe up to eighteen thousand people once lived there. Zimbabwe has a warm climate with a rainy season and a dry season. The land rises from low river valleys to a high central plateau. This flat area sits about four thousand feet above sea level. Most of the population lives on this plateau because the temperatures are cooler. Victoria Falls, one of the largest waterfalls in the world, sits on the Zambezi River at Zimbabwe's northern border. The local name for the falls is Mosi-oa-Tunya, which means the smoke that thunders.