The residents of the Sassi are never out of sight of the city’s soaring cathedral, completed in 1270 on high ground at the side of the cliff just above them. A wealth of carvings on the facade deliver a morality lesson to the faithful: A mermaid warns of the passions likely to steer us off a path of righteousness; an eagle is poised to devour meeker animals, just as we are always prey to sin; the Archangel Michael battles the dragon (representing the forces of evil) before an audience of the town’s medieval elite. Similarly moralistic frescoes once covered the interior; most were destroyed in many renovations, but a terrifying 13th-century Last Judgment remains, to the right of the entrance. Archangel Michael is here too, wielding his sword in hell, where serpents attack the damned—among them popes, monks, and kings, proof that no one escapes the final judgment. An antidote is the utterly charming 16th-century nativity scene in a side chapel, where shepherds and their flocks are set against a re-creation of Matera, looking just like it does today—just the sort of place where Christ would be born.