South Sudan, officially the Republic of South Sudan, is a landlocked country in Northeast Africa. It is bordered by Sudan to the north, Ethiopia to the east, Kenya to the southeast, Uganda to the south, the Democratic Republic of the Congo to the southwest, and the Central African Republic to the west. South Sudan's diverse landscape includes vast plains and plateaus, dry and tropical savannahs, inland floodplains, and forested mountains. The Nile River system is the defining physical feature of the country, running south to north across its center, which is dominated by a large swamp known as the Sudd. South Sudan has an estimated population of just over 12.7 million in 2024. Juba is the capital and largest city.