The White Hall served as premises for the fourth Astronomical Observatory in Europe, founded in 1753. In this Hall Baroque and Classicism are merged.
It has a remarkable portal with King Stanislaus Augustus Poniatowaki’s portrait in the centre of the tympanum.
An elliptical opening leads from the White Hall into a smaller hall above. It was used for astronomical observations.
Famous visitors to the city visited this Hall and admired the Observatory. A unique collection of ancient astronomical instruments is displayed in the White Hall.