Saarbrücken is the capital and largest city of the state of Saarland, Germany. Saarbrücken has 181,959 inhabitants and is Saarland's administrative, commercial and cultural centre. It is located on the Saar River, directly borders the French department of Moselle, and is Germany's second-westernmost state capital after Düsseldorf.

The Saar is a river in northeastern France and western Germany, and a right tributary of the Moselle. It rises in the Vosges mountains on the border of Alsace and Lorraine and flows northwards into the Moselle near Trier. It has two headstreams, that both start near Mont Donon, the highest peak of the northern Vosges. After 246 kilometres (153 mi) the Saar flows into the Moselle at Konz (Rhineland-Palatinate) between Trier and the Luxembourg border. It has a catchment area of 7,431 square kilometres (2,869 sq mi).