The "Quattro Canti" in Palermo

The heart and also the physical center of old Palermo is Piazza Vigliena (1608-1620), which has the shape of an octagon, also known as "I Quattro Canti" (The Four Cantons)" or "Teatro del Sole" (Theatre of the Sun) because at any time of day at least one of the cantons is illuminated from sunlight.