At the same time, it is also the administrative centre of the Verbandsgemeinde of Montabaur – a kind of collective municipality – to which 24 other communities belong.

The town is known throughout the country for its strikingly yellow castle and its InterCityExpress railway station on the Cologne-Frankfurt high-speed rail line.

Stretching south along the Gelbach valley are the pilgrimage centre of Wirzenborn, and, farther along still, Reckenthal, Bladernheim and Ettersdorf.

Montabaur's neighbours are, clockwise beginning in the north, Dernbach, Staudt, Heiligenroth, Großholbach, Girod, Steinefrenz, Heilberscheid, Isselbach, Stahlhofen, Untershausen, Holler, Niederelbert, Arzbach, Kadenbach, Neuhäusel, Nomborn and Hillscheid.

In 1945 the western Allies partitioned the northwestern part of the Wiesbaden Region with Montabaur and annexed it to the new German state of Rhineland-Palatinate.