The church takes its name from the vincoli (chains) that once held St. Peter (they're on display in the case under the altar), but throngs of tourists come to see Michelangelo's Moses, a powerful statue almost as famed as his frescoes in the Sistine Chapel. The Moses was destined for the tomb of Julius II, designed to be the largest in St. Peter's Basilica. But Julius's successors had Michelangelo work on other projects, and the tomb was never finished.