The White Tower is a defensive structure dated to the 15th century. Later, it was used as a guard's quarters by the Janissaries and as a prison for those who were convicted to death. It was built on the place where an older, Byzantine tower once stood. This Byzantine tower connected the east wall of the fortification of Thessaloniki (the part preserved today) with the sea wall, which was demolished in 1866.
The museum in the White Tower contains various collections of sculptures,
frescoes, fragments of mosaic floors and wall mosaics, icons, coins, inscriptions, pottery, glass and metal items.
The most important exhibits of the museum are: Fragment of a wall mosaic from the church of Saint Demetrius in Thessaloniki. It represents the Saint with two children. Dated to the 5th-6th century AD. Silver casket from Chalkidiki. It is decorated with scenes from the Old and the New
Testament. Dated to the late 4th century AD. Fresco from a grave, found in Thessaloniki. It bears the representation of the story
of Sosanna, recorded in the Old Testament. Dated to the second half of the 4th century AD. Fragment of silk cloth woven with gold thread. It was found in a man's grave, in the
basilica of Saint Achilleios at Lake Prespa. Dated to the 11th century AD. A couple of armlets made of gold and enamel, found in Thessaloniki. Dated to the 10th century. Icon depicting the Virgin with Christ Child. It was probably imported to Thessaloniki
from Cyprus. Dated to ca. 1200 AD.