Pforzheim is a city of over 120,000 inhabitants in the federal state of Baden-Württemberg, in the southwest of Germany. It is known for its jewelry and watch-making industry, and as such has gained the nickname "Goldstadt" ("Golden City"). With an area of 97.8 km2 (38 sq mi), it is situated between the cities of Stuttgart and Karlsruhe at the confluence of three rivers (Enz, Nagold and Würm). It marks the frontier between Baden and Württemberg, being located on Baden territory. From 1535 to 1565, it was the home to the Margraves of Baden-Pforzheim.