Spolia from all these ancient remains is still apparent in the church's construction, most particularly three columns from the Temple of Juno Sospita which are incorporated into both the 10th century and 1599 north façades of the church. The columns of the Temple of Janus, dedicated by Gaius Duilius after his naval victory at the Battle of Mylae in 260 BC, can still be seen as being incorporated into the wall of the church.