To the west of the Orangery Palace, in a pavilion flanking the main building, is the last remaining princely bathhouse from the Late Baroque era in Germany, the Marble Bathhouse. Its exterior conforms to the architectural style of the Orangery; its true splendour becomes evident once you enter it. Built as a pavilion in the years 1722 to 1728 under Landgrave Carl, the cubic structure originally was not used for bathing but as a venue for festive occasions and courtly events.
The Roman sculptor Pierre Étienne Monnot (1657–1733) created the magnificent interior featuring life-size marble statuary, highly detailed mural reliefs, and wall panels in coloured marble, making the Marble Bathroom one of the finest ensembles of early 18th-century Roman secular sculpture north of the Alps.