The facade of the extension, known as the Rotunda, has allegorical reliefs by Walter Runeberg, the son of the national poet and the artist behind numerous monumental sculptures of the late 19th century.
T here are nine reliefs, located on the pillars of the crescent-shaped wall.
They depicting female figures personifying arts and sciences. In addition, the symbol of each scientific discipline and its Latin name is found under each relief. The works contain a reference to the mediaeval practice of using female figures to represent the seven liberal arts. The symbols are modernized versions of themes rooted in Antiquity, and of established images and symbols of Western culture. B eginning from the right-hand corner, the reliefs depict Historia, Iuris prudentia, Philosophia, Ars, Medicina, Theologia, Astronomia, Physica and Historia.