The hypogeum of Piazza Duomo is an underground path that links in East-West direction piazza del Duomo to the walls of the Navy that consists of a main gallery, from which some smaller tunnels branch off, one of which joins the big cistern of the Archbishop's Palace. Built by Bishop Paul Pharoah (1619-1629), the tank had an essential role not only for the water supply of the Archbishop's Palace, but for the whole of Ortigia. During the journey you can see the remains of other ancient wells or cisterns, intercepted and destroyed during the excavation of the galleries.
A first group of galleries is tied to the presence of a former quarry located in Piazza Duomo and remembered in the eighteenth century because it was, is the stone for the building of the façade of the Cathedral. The access point was detected in 1869 during the making of "public works" almost to the front door of entrance of the Archbishop's Palace, but that was a little part of the monastery of St. Lucia: situated a large pulley, and for it the mastri raised stone which was of the same nature as that of columns ... " The events related to the second world war brought attention to the underground spaces identified in the previous century. In view of Italy's entry into the war, were designed by the City Committee of the U.M.P.A. (military anti-aircraft protection Union) collection points for the civilian population in case of attack. To prepare the bomb shelter in Piazza Duomo were called "pirriatori" teams tasked with widening the ancient quarry, digging a room where store in zinc boxes the simulacrum of Saint Lucia, hidden since December 1942 with the treasure, and provide access for the population in the retaining wall of the Archbishop's garden with an additional entrance to the galleries in the old wall of the Marina. It was therefore created an underground path that connected the piazza del Duomo to the Navy, through a joint Gallery in North-South direction, to the tank. After the war, it s carried out at Lee's disposal. Now memories tied to history, delivered the bomb shelter of piazza del Duomo – at par with any witness, architectural or otherwise, that make up the millennial history of urbanism Ortigia-looks like only, final outcome of complex layering man-made site, which collects in its components-including the cistern is the oldest historically-related contributions at different stages of history.