Wiesbaden is the capital of the German state of Hesse, and the second-largest Hessian city after Frankfurt am Main. With around 283,000 in…Wiesbaden is the capital of the German state of Hesse, and the second-largest Hessian city after Frankfurt am Main. With around 283,000 inhabitants, it is Germany's 24th-largest city. Wiesbaden forms a conurbation with a population of around 500,000 with the neighbouring city of Mainz. This conurbation is in turn embedded in the Rhine-Main Metropolitan Region—Germany's second-largest metropolitan region after Rhine-Ruhr—which also includes the nearby cities of Frankfurt am Main, Darmstadt, Offenbach am Main, and Hanau, and has a combined population exceeding 5.8 million.