Studiolo of Isabella d'Este

Image 1: Pentagram on the Ceiling of the Studiolo, Palazzo Ducale of Mantua. Source: Wikimedia, FranzK. Copyright: CC BY-SA 4.0.

Image 2: View of the Palazzo Ducale of Mantua. Source: David Nicholls on Flickr. CC BY-NC 2.0 (Attribution Non-Commercial 2.0 Generic).