Cottbus or Chóśebuz is a university city and the second-largest city in the German state of Brandenburg after the state capital of Potsdam. With around 98,000 inhabitants, it is the most populous city in Lusatia. Cottbus lies in the Sorbian settlement area of Lower Lusatia, and is the second-largest city on the River Spree after Berlin, from which it is situated around 125 km upstream. The city is located on the shores of Cottbus Eastern Lake, which will be Germany's largest artificial lake by surface area when flooding is completed.