Built by Constantine on the site of St Paul's tomb, the basilica was almost entirely destroyed by fire in 1823 and then immediately rebuilt. The interior is breathtakingly grand. Marking the site of the Saint's burial, the Gothic-style ciborium is an exercise in harmony and finesse by Arnolfo di Cambio. On the right, note the 12C Romanesque paschal chandelier attributed to Vassalletto. Finally, the pretty cloister adjacent to the church is well worth a visit.