The coat of arms in marble of Pope Alexander VII documents the 17th century restoration made with salvaged bricks of various sizes, arranged haphazardly in undulating rows. Visible on the lower part of the brickwork are 19th century restorations, and at the ends, areas of plastered masonry. On the upper part are modern restorations. On the interior side of the walls, the brick curtain wall dates to Honorius with an embrasure within a niche, lined with herringbone bricks in the spherical cap-shaped ceiling.
