The bottom-floor of the south tower is, in terms of liturgical considerations, a particular spot: namely, it is a Chapel.
An Apse can be found in the hollowed-out east wall of the tower, which was uncovered during the recent bricking lining work. To great surprise, still recognizable middle-aged paintings were found upon the inner-plaster of the Apse. Although a final assessment from art historians is still pending, it is expected that the paintings found here are of great importance in terms of European art.