Basilica of San Pietro in Vincoli (St. Peter in Chains)

Houses Michelangelo's terrifying Moses (1515) — centrepiece of the unfinished tomb of Pope Julius II, originally designed to include 40 statues but reduced to 7 after decades of frustrating delays that Michelangelo called 'the tragedy of the tomb.' The marble Moses, with its disquieting horns (a medieval mistranslation of the Hebrew word for 'rays of light'), is so intensely realised that visitors say it seems about to stand up and speak. The basilica also holds the chains traditionally believed to have bound Saint Peter both in Jerusalem and in his Roman prison — when the two sets were brought together in the 5th century, they reportedly fused miraculously into one. Free entry.