Mappe stellari e geometria sacra nel disegno delle città medioevali di Sicilia. Un’ipotesi archeoastronomica su Erice

Already in his studies on the Middle Ages cities E. Guidoni suggested the possibility of an urban design governed not only by precise astronomical alignments, but by a figurative conception, of a zoomorphic or anthropomorphic type, whose aim was to reproduce on the ground the zodiacal constellations. The envelopes and sinuosities of the plots that distinguish the medieval cities would be dictated by an iconographic program in which certain emergencies (churches, towers, domes) and the main connection roads would be arranged in a mirror-or perspective-view of the celestial maps with respect to certain observation points at the meridian or on the horizon of the place. Some examples would be emblematic of this operating method. As far as Sicily is concerned, a similar hypothesis has already been put forward on Randazzo, in which emergencies and planimetric layout would reproduce the Virgo constellation in plan. Carrying out this suggestion, and focusing attention on the cities founded or re-founded by the Altavilla, the contribution explores the possible archaeoastronomic design - and the symbolic and mythical meanings connected to it - of the Norman town of Erice.