One of Rome’s seven pilgrimage churches, the Church of the Holy Cross in Jerusalem was founded in 320 by St Helena, mother of the emperor Constantine, in the grounds of her Roman palace. It takes its name from the Christian relics here – including a piece of the cross on which Jesus was crucified and a nail from the crucifixion – that St Helena supposedly brought to Rome from Jerusalem. These are housed in a modern chapel to the left of the altar.
Of particular note are the lovely 15th-century Renaissance apse frescoes representing the legends of Christ's cross, showing where the wood came from and how it was turned into the cross.