South Sudan is bordered by Sudan to the north. Khartoum is the capital and largest city of Sudan. Juba is the capital and largest city of the Republic of South Sudan. South Sudan is the world's newest country. South Sudan declared independence from Sudan on July 9, 2011.
Juba is one of the major cities in South Sudan. It would be a good starting place for travels in South Sudan. Be advised that there is very little security in South Sudan and there is fighting there on occasion.