With around , inhabitants, it is Germany's 24th-largest city. Wiesbaden forms a conurbation with a population of around , with the neighbouring city of Mainz. This conurbation is in turn embedded in the Rhine-Main Metropolitan Region βGermany's second-largest metropolitan region after Rhine-Ruhr βwhich also includes the nearby cities of Frankfurt am Main , Darmstadt , Offenbach am Main , and Hanau , and has a combined population exceeding 5.
The city is located on the Rhine Upper Rhine , at the foothills of the Taunus , opposite the Rhineland-Palatine capital of Mainz , and the city centre is located in the wide valley of the small Salzbach stream. Wiesbaden lies in the Rheingau wine-growing region , one of Germany's 13 wine regions. Historically, Wiesbaden was a Nassauian city. From to , it lay in the County of Nassau , and from to , it was in the county and later principality of Nassau-Idstein, all of which were territories within the Holy Roman Empire ruled by branches of the House of Nassau.
In , the city found itself in the principality of Nassau-Usingen , and in , Biebrich Palace became the main residence of the House of Nassau-Usingen. In , the city became the capital of the Duchy of Nassau. Since , the newly built Wiesbaden City Palace was the principal Nassauian residence. From to , the city lay in the Prussian Province of Hesse-Nassau , and from to , it was the capital of the Province of Nassau.
In , it became the capital of Greater Hesse and subsequently, in , of Hesse. Wiesbaden is one of the oldest spa towns in Europe. Its name translates to "meadow baths", and there are 15 mineral springs β14 of which are hot springs βin the city centre.
Its location in a mountain basin at the southern foot of the Taunus , protected by the mountains in the north and west, gives Wiesbaden a mild climate. It has been called the " Nice of the North" because of its climate and architecture.
