THE BASILICA DI SANT’ANDREA STANDS in Mantua’s historical center, overlooking the Piazza Mantegna. In the crypt are kept two reliquaries with earth soaked in the blood of Christ.

Christian tradition holds that while Jesus was being crucified, a Roman soldier named Longinus pierced his side with a lance. After Jesus died, Longinus repented for his sin and collected the blood-soaked soil from underneath the cross.