Above the underground Aboa Vetus is the the former Rettig palace which now functions as a museum of contemporary arts – Ars Nova. The first floor of Ars Nova displays annually four changing exhibitions while an exhibition from Matti Koivurinta Foundation's art collection can be found on the second floor twice a year. Some of the temporary exhibitons also fill Ars Nova's second floor. This is also where Takkahuone-gallery is located.
Ars Nova has a space of all together 600 square metres reserved for contemporary art. The Rettig palace, which was originally designed as a private home for the Rettig family, now functions as an art museum. Exhibition rooms of various sizes go around the second floor of Ars Nova – together these rooms form an intimate space. The first floor shows merely small signs of the space's original purpose as the palace's cellar.
Several bedrooms of the Rettig family were once located on the Ars Nova's second floor. Original interior design can still be seen in the exhibition space, e.g. a green marble bathroom or a hall covered with hardwood. The second floor is very different from Ars Nova's first floor as an exhibiton space mainly because from the upper floor the viewer can admire the fantastic view over the Rettigrinne's garden and Nunnankatu.