Elector Wilhelm II had the Great Greenhouse built in 1822 to house his diverse collection of exotic plants. The delicate structure was one of the earliest glass-steel constructions in Europe. An elaborate heating system provided pleasant temperatures throughout the winter. Here the frost-sensitive plants could overwinter, while the Elector used the house for representation: In the round central section (salon) he received his guests for tea and showed the valuable plant collection. The central section acquired its present rectangular form during a renovation around 1888. In that context the warmhouse plants were also moved into the new central section.

Even today, visitors to the Great Greenhouse can admire a sea of color of orchids, palms, camellias, bananas and other exotic plants during the season. In spring, some of the plants, in keeping with old tradition, adorn the outdoor areas of the Bergpark Wilhelmshöhe.