This towering basilica safeguards the golden vessels said to hold earth soaked by the blood of Christ. Longinus, the Roman soldier who speared Christ on the cross, is said to have scooped up the earth and buried it in Mantua after leaving Palestine. Today, these containers rest beneath a marble octagon in front of the altar and are paraded around Mantua in a grand procession on Good Friday.

Ludovico II Gonzaga commissioned Leon Battista Alberti to design the basilica in 1472. Its vast, arched interior is free from pillars and has just one sweeping central aisle, which is dotted with frescoes, gilded ceiling bosses and columns cleverly painted to look like carved stone.

The first chapel on the left contains the tomb of Andrea Mantegna, the man responsible for the splendours of Mantua's most famous paintings – those in the Camera degli Sposi in the Palazzo Ducale. The chapel is beautifully lit and also contains a painting of the Holy Family and John the Baptist, attributed to Mantegna and his school.