They were designed for multiple purposes: escape routes in case of attacks, and secret connections between the main buildings of the city center. Over time, many of these structures were converted into sewers for noble palaces, thus losing their original function and part of their memory.
According to tradition, the Moncada family had a gallery built that connected almost all the main churches of the city. Specifically:
- From the crypt of the Church of Santa Flavia, there would be a doorway leading toward the heart of the city, giving access to a secret passage that reached Palazzo Moncada.
- Palazzo Moncada, however, currently shows no known entrances or exits to tunnels — understandable, considering it was never completed.
- From the Church of Sant’Agata al Collegio, a tunnel would lead to the Cathedral of Santa Maria La Nova.
- From the Cathedral, two tunnels: a short one to the Church of San Sebastiano, just opposite, and another extending to the Church of Santa Croce and its old convent.
- From the Church of Santa Croce, another passage would lead to the Church of San Domenico. In this very gallery, according to some accounts, the remains of infants were found — but that is another story, with even darker overtones.
- Finally, from the Church of San Domenico, the last known tunnel would reach the Castle of Pietrarossa, continuing into a hidden passage that exited beyond the city walls: a true escape route, strategically concealed.
The last known access to one of these tunnels dates back to the 1970s, when a young man managed to walk a section underground starting from San Domenico. After that episode, the entrance was quickly sealed and made inaccessible to the public.