The hall is square and stands out for its rich interior decoration of frescoes that completely line the walls. Here, a sequence of mixtilinear, channeled, Ionic columns support a dual architrave adorned by masks and rich festoons. This imposing but refined architectural structure incorporating the real opening of room doors have as background, a rich landscape with allegorical symbolisms, painted under a blue sky lined with clouds.
The southern wall is decorated by a woody landscape, with hills, little houses and a small waterfall, acting as background to the great capital on which a marble niche was painted, portraying a golden monochrome of “Nembrot with the Tower of Babel” and the almost completely last inscription, “OMEN / (16)65.”
Lastly, the west wall is adorned by an ulterior, partially destroyed arch rising above a courtyard featuring a central fountain and niches decorated with statues, among which in the foreground, the goddess, Minerva, stands out.
As often occurring in the Arese decorations, also in this hall the different pictorial elements, taken from biblical stories or mythology or as simple landscape subjects, concur to formulate precise warnings referring to the life of Bartolomeo III Arese and connected to his family’s history. The main theme of the narration in the Room of faux architecture is the construction of the majestic Arese palace, achieved under the supervision of the Arese family and the two branches of the Borromeo family, here represented by the storks flying in the sky on the north wall: in fact Bartolomeo would leave the Cesano villa to the Borromeo family after the death of his son, an event he considered as a divine punishment for the arrogance of his earthly plans, in line with the story of the Tower of Babel. According to some historians this hall, however, also contains a positive vision of the personal story of Bartolomeo Arese, as is symbolically testified to by the images of the stream and goddess, Minerva, on the west wall. In fact, it is this contact with nature and the study of science that will provide purification of the sins of the Arese nobleman.
The complex decoration of this hall, in particular, gave the scholars the chance to propose other iconographic interpretations on a political perspective, such as that of the figure of Nembrot (or Nimrod). The defeats suffered in the Thirty Years War and in the French-Spanish conflict could in fact be interpreted as the fulfillment of the divine will that Spain should not be punished but simply purified so as to conduct her to the final redemption.
Critiques attribute the execution of the wall decorations to the Milanese painter, Giovanni Ghisolfi (1623-1683), who trained in the Roman workshop of Salvator Rosa and was thus perfectly updated on the lessons of the artists of Claude Lorrain, strongly influenced the manner of conceiving and painting seascapes.