is a five-aisled basilica, with a narthex and a transept. Under the
sanctuary and the transept there is the crypt. A chapel of Saint Euthymios is
attached to the south-east corner of the church. Very few fragments of the sculptural
and pictorial (mosaics, wall paintings) decoration of the church, survived the
disastrous fire of 1917 but they are representative of the successive phases of
the monument's history.
The first church was a small oratory, built shortly after 313 A.D.
on the ruins of a Roman bath. In the 5th century A.D., the eparch Leontios founded
on the same site a large, three-aisled basilica which was burnt down in 626-634.
Shortly thereafter, the five-aisled basilica was erected. It was converted into
a mosque in 1493, it was restored to Christian worship in 1912 but it was again
destroyed in the great fire of 1917. It was rebuilt and started to function again
During the restoration of the monument after the fire of 1917, several
trenches were opened in the naos and the crypt. Systematic excavations were carried
out in 1946-49.
Restoration of the church was undertaken immediately after the catastrophe
of 1917. Work was stopped in 1938 and was again resumed in 1946. The monument
was rebuilt and started to function again in 1949. Today the monument is used
as a church.
In the crypt of Aghios Demetrios, an exhibition is on display to
the public. It includes the items that survived the fire of 1917 and those that
were brought to light by the recent excavations in the monument.