Wiesbaden in the context of "Duchy of Nassau"

The Main (German pronunciation: [ˈmaɪn] ) is the longest tributary of the Rhine, one of the major European rivers. It rises as the White Main in the Fichtel Mountains of northeastern Bavaria and flows west through central Germany for 525 kilometres (326 mi) to meet the Rhine below Rüsselsheim, Hesse. The cities of Mainz and Wiesbaden are close to the confluence.

The largest cities on the Main are Frankfurt am Main, Offenbach am Main and Würzburg. It is the longest river lying entirely in Germany (if the Weser-Werra are considered separate).

The Rhine-Main Metropolitan Region, often simply referred to as Frankfurt Rhine-Main, Frankfurt Rhine-Main area or Rhine-Main area (German: Rhein-Main-Gebiet, Frankfurt/Rhein-Main or FrankfurtRheinMain, abbreviated FRM), is the third-largest metropolitan region in Germany after Rhine-Ruhr and Berlin-Brandenburg, with a total population exceeding 5.9 million. The metropolitan region is located in the central-western part of Germany, and stretches over parts of three German states: Hesse, Rhineland-Palatinate, and Bavaria. The largest cities in the region are Frankfurt am Main, Wiesbaden, Mainz, Darmstadt, Offenbach, Worms, Hanau, and Aschaffenburg.

The polycentric region is named after its core city, Frankfurt, and the two rivers Rhine and Main. The Frankfurt Rhine-Main area is officially designated as a European Metropolitan region by the German Federal Ministry of Transport, Building and Urban Affairs and covers an area of roughly 13,000 square kilometers (5,000 sq mi).

Darmstadt (/ˈdɑːrmstæt/ DARM-stat, UK also /-ʃtæt/ -⁠shtat, US also /-stɑːt, -ʃtɑːt/ -⁠s(h)taht, German: [ˈdaʁmʃtat] ) is a city in the state of Hesse in Germany, located in the southern part of the Rhine-Main-Area (Frankfurt Metropolitan Region). Darmstadt has around 160,000 inhabitants, making it the fourth largest city in the state of Hesse after Frankfurt am Main, Wiesbaden, and Kassel.

Darmstadt holds the official title "City of Science" (German: Wissenschaftsstadt) as it is a major centre of scientific institutions, universities, and high-technology companies. The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and the European Space Agency's European Space Operations Centre (ESA ESOC) are located in Darmstadt, as well as GSI Centre for Heavy Ion Research, where several chemical elements such as darmstadtium, roentgenium, and copernicium were discovered. The existence of several elements was also confirmed at the GSI Centre. The Facility for Antiproton and Ion Research (FAIR) is an international accelerator facility under construction. Darmstadt is also the seat of the world's oldest pharmaceutical company, Merck, which is the city's largest employer.

Hesse or Hessen (German: Hessen [ˈhɛsn̩] ), officially the State of Hesse (German: Land Hessen), is a state in Germany. Its capital city is Wiesbaden, and the largest urban area is Frankfurt, which is also the country's principal financial centre. Two other major historic cities are Darmstadt and Kassel. With an area of 21,114.73 square kilometers and a population of over six million, it ranks seventh and fifth, respectively, among the sixteen German states. Frankfurt Rhine-Main, Germany's second-largest metropolitan area (after Rhine-Ruhr), is mainly located in Hesse.

As a cultural region, Hesse also includes the area known as Rhenish Hesse (Rheinhessen) in the neighboring state of Rhineland-Palatinate.

Mainz (German: [maɪnts] ; see below) is the capital and largest city of the German state of Rhineland-Palatinate, and with around 223,000 inhabitants, it is Germany's 35th-largest city. It lies in the Rhine-Main Metropolitan Region—Germany's second-largest metropolitan region after Rhine-Ruhr—which also encompasses the cities of Frankfurt am Main, Wiesbaden, Darmstadt, Offenbach am Main, and Hanau.

Mainz is located at the northern end of the Upper Rhine Plain, on the left bank of the Rhine. It is the largest city of Rhenish Hesse, a region of Rhineland-Palatinate that was historically part of Hesse, and is one of Germany's most important wine regions because of its mild climate. Mainz is connected to Frankfurt am Main by the Rhine-Main S-Bahn rapid transit system. Before 1945, Mainz had six boroughs on the other side of the Rhine (see: de:Rechtsrheinische Stadtteile von Mainz). Three have been incorporated into Wiesbaden (see: de:AKK-Konflikt), and three are now independent.

Germania Superior ("Upper Germania") was an imperial province of the Roman Empire. It comprised an area of today's western Switzerland, the French Jura and Alsace regions, and southwestern Germany. Important cities were Besançon (Vesontio), Strasbourg (Argentoratum), Wiesbaden (Aquae Mattiacae), and Germania Superior's capital, Mainz (Mogontiacum). It comprised the Middle Rhine, bordering on the Limes Germanicus, and on the Alpine province of Raetia to the south-east. Although it had been occupied militarily since the reign of Augustus, Germania Superior (along with Germania Inferior) was not made into an official province until c. 85 AD.

The Taunus (German pronunciation: [ˈtaʊnʊs] ) is a mountain range in Hesse and Rhineland-Palatinate, Germany, located north west of Frankfurt and north of Wiesbaden. The tallest peak in the range is Großer Feldberg at 878 m; other notable peaks are Kleiner Feldberg (825 m) and Altkönig (798 m).

The range is bounded on three sides (west, north, and south) by the Rhine and its tributaries, namely the Lahn and the Main, and on the east by the plain of Wetterau. It spans the districts of Hochtaunuskreis, Main-Taunus-Kreis, Rheingau-Taunus, Limburg-Weilburg, and Rhein-Lahn. The range is known for its geothermal springs and mineral waters that formerly attracted members of the European aristocracy to its spa towns. The car line Ford Taunus is named after it.