The impressive St Demetrios' Church (Ágios Dimítrios) marks the site of the martyrdom and tomb of St Demetrios, patron saint of Thessaloníki. After the fire in 1917 the church was totally restored to reproduce the 7C basilica that was preceded by an atrium; some of the old material was re-used. The pillars on either side of the entrance to the apse are decorated with small 7C mosaics of remarkably fine design and colouring.