At the southeast corner of the old cathedral, a humble opening leads to the chapel of St Demetrios. The elegant chapel that no longer has a dome preserves fragments of Byzantine frescoes of the early 14th century. The few surviving faces allow the visitor to guess at what the unknown painter's work in the great metropolises of the day – perhaps churches in Thessaloniki or even Konstantinople – would have been like, if any still existed today.
