The support columns of the church walls, normally erected outside the church, were constructed inside and so created small parcelled sectors which accommodated 44 medieval guild and craft altars during the Catholic period. Today, both aisles provide room for burial chapels which
were mostly erected with Baroque display walls.

Next to the South Portal stands the wooden Baroque Baptistry, built in 1738, with its 16th- century font. These days, it has again become the place for baptisms during services