The Belvedere (1789-90), a charming construction by Carl Gotthard Langhans, is built in a combination of Baroque and neo-Classical style. Once used by Frederick William II for his spiritualist meetings, it boasts a simple façade in pastel and white tones, the style of which is more neo-Classical than Rococo. The building houses a small museum of the Royal Berlin Porcelain Factory which displays exhibits relating to the Berlin porcelain industry of the 18C and 19C.