For centuries, the Lower Castle was the residence of the Lower Greiz lords and imperial counts as well as the Reuss princes of the older line. The Lower Castle houses a permanent exhibition, a textile showroom and changing special exhibitions.

The permanent exhibition in the Lower Castle presents the continuation of the exhibition "From the Land of the Bailiffs to the Principality of Reuss Older Line" in authentic rooms from the 19th century. The highlight is the ballroom on the Beletage, the former representation and living quarters of the princes. The gallery with conservatory and the rooms of the sovereigns decorated with stucco and friezes are also worth a visit.

The textile show workshop deals with the history of the Greiz textile trade from its beginnings in 1450 to the industrial production of textiles. The show workshop is located in the former utility rooms of the farm. Visitors can experience and feel the history of Greiz by actively participating in the production process on hand looms, weaving machines and winding machines.