Merenberg lies on the southern edge of the Westerwald between the district seat of Limburg and Weilburg.

On both the Almerskopf and the Höhburg are found remnants of settlements from La Tène times.

In the course of administrative reform in Hesse, the formerly autonomous communities of Allendorf, Barig-Selbenhausen, Merenberg, Reichenborn and Rückershausen, which had all belonged to the old Oberlahnkreis (district), merged into the new collective community of Merenberg.

Besides the trade and crafts that are customary for such a place, there are a few small and medium-size industrial businesses.

The community lies on Bundesstraße 49, which is currently (February 2006) being widened to four lanes between Limburg and Wetzlar, and which links Merenberg to the long-distance road network.