The tomb is situated near the ruined church of San Pietro, of which only the 18C façade, complete with its decorative rose window, remains. Named after a Lombard king, the tomb of Rotharis rests on a square structure which rises in stages through an octagon and then a triangle to a dome. The most recent restoration work revealed a cistern which is thought to have been used for full immersion baptism, suggesting that the building was not a tomb at all but a baptistery.