At the end of Calle dell’Aseo, where the calle closes against an enclosure wall, there rests against the wall something that should not exist: exactly half of a vera da pozzo (a wellhead). Its profile, step and perforated mouth are cut cleanly, like a cake in half; the other half continues beyond the wall, in a private courtyard invisible from the street. If this vera now touches a wall, the reason lies in the wall itself: it came later.