Perched on a gentle green hill, the white marble fortress of Castel del Monte is an example of medieval architecture. Built under Frederick II of Swabia, it reflects the Emperor's humanist ideas. Emperor of the Holy Roman Empire and later King of Sicily, he was one of the most fascinating figures in medieval history and the protagonist of many legends. He was passionate about mathematics, poetry, philosophy, and astronomy, so he welcomed Greek, Arab, Italian, and Jewish scholars to his court. This octagonal building harmoniously blends elements of classical architecture with decorations typical of Arab architecture in Europe. The number eight's recurrence makes the Castel del Monte fortress an esoteric place, but some scholars hypothesized it could even be a hammam. While admiring the formal perfection of this UNESCO World Heritage Site, you can discuss with your guide the possible functions of this impressive fortress.