Wau is a city in South Sudan. It lies on the western bank of the Jur River, in Wau County, Western Bahr el Ghazal State, in northwestern South Sudan. Its location lies approximately 650 kilometres (400 mi), northwest of Juba, the capital and largest city in that country. Wau was initially established as a zariba (fortified base) by slave-traders in the 19th century. During the time of Anglo-Egyptian condominium rule in Sudan, the city became an administrative center.