The Byzantine Bath in Thessaloniki is one of the few and best preserved of the Byzantine baths that have survived from the Byzantine period in Greece.
The baths date to the late 12th/early 13th century, and functioned continuously until 1940, when they shut down probably due to World War II and the German occupation of Greece. The Byzantine sources do not mention it, hence it is likely that it originally belonged to a monastery complex.
The bath's long use led to numerous alterations of the original structure over time. The original architecture follows the typical conventions of Roman baths. The original entrance in the south leads to the rectangular frigidarium rooms, which were used as dressing rooms. Then came two vaulted tepidarium rooms and finally two caldarium rooms. The latter were square in shape and featured hypocausts below the floor. One was covered by a dome supported by an octagonal base with eight windows, the other had a domed ceiling. To the north of the baths was the cistern that provided it with water, with a hearth beneath to warm it. In Byzantine times the building was alternately used by men and women, but in the Ottoman period the bath was divided into exclusively male and female sections, by blocking off each pair of rooms from each other.
The bath was one of several in the city, but is the only surviving in Thessaloniki and the largest and most complete of the handful of Byzantine baths surviving elsewhere in Greece.
In 1988, it was included among the Paleochristian and Byzantine monuments of Thessaloniki on the list of World Heritage Sites by UNESCO.
Following four years of restoration work, the bath was re-opened to the public as a museum and cultural space in June 2015.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.