Sasolburg is a town in the Free State province of South Africa. It is located on the Vaal River, about 30 km south of Johannesburg. Sasolburg was established in 1954 and is the site of the Sasolburg Oil Refinery, the largest oil refinery in the Southern Hemisphere. The town is home to a number of chemical and other industries, and its economy is heavily dependent on these industries. However, the town also has a number of tourist attractions, including the Sasolburg Museum, the Vaal Dam, and the Vredefort Dome World Heritage Site.