Originally built as a centrally planned building on the axis of the monumental street connecting the triumphal arch of Galerius with the palace complex. There are varying opinions on its use, such as being a temple of Zeus or the Cabeiri, a building of a possibly devotional and secular - administrative character that served the needs of the palace complex, or a monument dedicated to the glory of Constantine the Great. The monument, with a diameter of 24.50m is covered by a bricked dome, reaching a height of 29.80m. The 6.30m - thick cylindrical wall internally inscribes eight rectangular niches, the south niche serving as the main entrance.

The building was converted into a Christian church, possibly dedicated to the Aghioi Asomatoi or the Archangels, during the Early Christian era. A gallery was added along its perimeter and in order to communicate with the original core, seven of the eight niches along the walls were demolished, the eastern niches being expanded with the addition of a sanctuary, a new entrance with a narthex being created at the western niches and a propylon and two chapels being added at the south entrance. However, the most magnificent remains from the Early Christian phase of the monument are its excellent mosaics that decorate the arches of the niches and the intrados of the windows, while the glorious decoration reaches its climax with the mosaics of the dome in three zones. Earthquakes in the early 7th century caused the destruction of the sanctuary's arch, the section above the dome and, possibly, the gallery. After being restored, the arch was externally strengthened with two buttresses and was decorated in the 9th century with a mural of the Ascension.

The history of the city is recorded on its walls and, at times, on the extant inscriptions, bearing witness to the repeated repairs and reconstructions of the walls over the course of the centuries. Remains from the Hellenistic and, subsequently, Roman fortifications of the city were incorporated in the late 4th century into the new fortification wall, trapezoid in shape, which encompassed Thessaloniki. The total perimeter of the city walls comes to 8km. On the plains, strong triangular redans alternated with square towers, while the wall was also strengthened with an outwork. On the sea side, the city was protected by a low fortification wall.

Western walls

Part of the Early Christian wall and outwork is preserved at Dimokratias Square. This is where the main entrance to the city, the Golden Gate, stood until 1874, when it was demolished, serving as the starting point to the main road of the city, the Roman decumanus maximus and, subsequently, the Byzantine Leoforos. Part of the wall continues uphill along present - day Irinis Street, up to its junction with Aghiou Dimitriou Street, where the second main decumanus of the city was situated. This is where the second main gate of the city from the west, Litea, was located, leading to the provinces, the Mygdonian cirque and Liti.

North - western Walls

The walls heading up towards the Acropolis follow the rocky geomorphology of the terrain. The NW section of the wall was added during the reign of Manuel II Palaeologus, who served as Despot of Thessaloniki from 1369 to 1373.

Acropolis Walls - Laparda
Tower - Anna Palaeologina
Gate - Trigonion Tower or
Alysseos Tower

The so - called intermediate wall (diameso) that separated the Acropolis from Ano Poli (the Upper City) extended to the west, approximately opposite Vlatadon Monastery, and reached Trigonion Tower to the east. The erection of towers on the intermediate wall towards the interior of the Acropolis, which originally formed the external facade of the city wall, confirms the subsequent addition of the Acropolis to the initial fortification walls. The extant inscriptions on the rectangular tower known as Laparda Tower, which stands opposite Vlatadon Monastery, concern the extensive interventions on the fortification of the Acropolis in the 12th century.
Following the intermediate wall towards the NE stands the Gate of Anna Paleologina (1355 - 1356), as noted on the inscription carved into the marble doorframe. This gate led to the area outside the walls. The intermediate wall ends in the NE at Alysseos Tower or, as it is better known, Trigonion Tower. This is a circular tower constructed in the 15th century, incorporating an older square tower that stood at that location, forming part of the Byzantine fortifications. Trigonion Tower, along with the Vardaris Fort and the White Tower, were incorporated in the new fortification strengthening the defending system applied by the Ottomans in their effort to adapt to changes in military tactics brought about by the use of gunpowder.

Walls - White Tower - Outwork

The walls, at times built on rocky hills and at times on the remains of Roman fortifications, head downwards, proud and stately, to Aghiou Dimitriou Street and from there, almost humble, after 1889, to the sea. Through Filikis Etairias Street, where visible sections of the outwork and triangular redans of the main wall are preserved, they reach the White Tower, which stands at the junction of the sea wall and the land wall. The tower, in its present - day form, was built in the 15th century as a part of the modernisation of fortifications, replacing an older Byzantine tower.
From the gates of the eastern section of the wall, the locations of two main gates are known, situated on the two main road axes of the city: the New Golden Gate, corresponding to the Litea Gate, and the Cassandreotiki Gate (or Kalamaria Gate), corresponding to the Golden Gate.

Heptapyrgion

The Heptapyrgion fort stands at the highest point of the Acropolis, on the NE end of the city walls. It is a complex of various construction phases from the Early Christian - early Byzantine period up to the years of Ottoman rule, with the addition of newer buildings and auxiliary areas when it was converted into a prison in the 19th century, and, finally, during the late 1990s, mild interventions and necessary conversion took place so that the building could house the offices of the 9th Ephorate of Byzantine Antiquities. On the walls of the fort complex, with its numerous ceramoplastic and marble architectural elements from various eras incorporated at various points, numerous phases of construction can be detected, equal and corresponding in number, and the many adventures of the building over time, interwoven with the long and tumultuous history of the city, are depicted. The original core of the fort consists of ten towers, eight four - sided ones and two triangular ones, along with their intermediate sections, the oldest being the northern section, which was incorporated in the layout of the Early Christian fortification of the Acropolis, with numerous subsequent interventions. During the Middle Byzantine era, the towers on the southern side were added, completing the enclosure of the fort. The marble Ottoman inscription of 1431, built into the wall above the transom of the main entrance, denotes interventions and renovations to towers and sections of the fort during the years after the conquest of the city and its last refuge, the Heptapyrgion. Written sources on the fort are either silent, as is the case in the early Byzantine era, or sparing and confused, as is the case in the Middle and Late Byzantine eras, where references to the Koulas of Thessaloniki are at times related to the Heptapyrgion and at times to the Acropolis. The name Heptapyrgion occurs during the Ottoman era, possibly imitating Yedi Kule (Seven Towers), a 15th century fort in Istanbul with an equal number of towers, indeed. The monument burdened with its very recent memory of being a prison, which its new use not only failed to eradicate but actually preserved and showcased in the exhibition operating on the ground floor of one of the newer buildings of the complex, is open to the public of the city, while its premises, both open and closed, are made available for cultural events under the auspices of the 9th Ephorate of Byzantine Antiquities.

The small church is located in the Ano Poli, at the cul de sac of Aghias Sofias Street. It was once the catholicon of the monastery of Christou Sotira tou Latomou or ton Latomon, a name due to the existence of stone quarries in the area. The church was built in the late 5th century in the cross - in - square type with an apse on the east side. Today, the eastern half of the original facade has survived. The church is primarily known for its mosaic of the vision of Prophet Ezekiel in its apse, one of the most important mosaics of the Early Christian era.

Situated on the Aghiou Dimitriou Street, north of the ancient Agora and the Byzantine Megalophoros, built on the ruins of a Roman bath complex, this was where Demetrius, an officer in the Roman Army, was imprisoned and martyred in 303. A small private chapel was first built there. In the mid - 5th century, Leontius, prefect of Illyricum, erect a large basilica at the same location, which burned down during the earthquake of 620. With the contribution of Prefect Leontius and the Bishop of Thessaloniki, the basilica was restored to its original form of a five - aisled wooden - roofed basilica with a transept and gallery. The present - day restored form of the church - which was destroyed almost completely in the fire of 1917 - is the result of extensive restoration works that began in 1918 and ended in 1948. The tomb of the saint is located in the NW corner, where it was believed to have stood in the Early - Christian era. The church, dedicated to the patron saint of Thessaloniki, is a pilgrim church and is primarily renowned for its mosaics that survived the great fire of 1917. Eleven votive mosaics of the 5th, 7th and 9th century are preserved at the two pillars of the sanctuary and at the western wall of the central aisle.

The Great Church of the Virgin Mary is situated in the centre of the city on Aghias Sofias Street. It was built in the 5th century as a three - aisled wooden - roofed basilica with a narthex and gallery, over the ruins of a Roman bath complex. A small alcoved building connected to its south side served the worshipping needs of the church, while a small chapel dedicated to Aghia Irene was attached to the eastern side during the Byzantine period. The Basilica interior stands out for its architectural sculptures on the colonnades separating the three aisles, while excellent mosaics are also preserved on the intrados of the arches of the colonnade, the galleries and the trivelon (arcade) in the narthex.

This church, dedicated to Christ, the true Word and Wisdom of God, was built in the late 7th - early 8th century at the location of a large 5th century Early Christian Basilica. It is a typical example of a domed transitional cruciform church with ambulatory, in imitation of the Aghia Sophia in Constantinople. The mosaic decoration in its interior, a work of three stages, testifies to the high intellectual and artistic level of the city throughout the centuries. The decoration of the sanctuary is one of the most important precisely dated paintings of the Iconoclastic period (780 - 788). The Ascension depicted on the dome is a superb example of the so - called Renaissance of the Macedonian Emperors in the late 9th century, while the Virgin Enthroned with Christ in the apse, a work of the 11th - 12th century, covered the great iconoclastic cross.

The Church dedicated to the Virgin Mary is located south of the ancient agora, at the SE corner of the Byzantine Megalophoros, in the coppersmith district from where its name is derived. It is a precisely dated monument with an inscription on the marble lintel of the western entrance: It was built in 1028 as a sepulchral chapel, by Christophoros, Protospatharios and Katepano (Governor) of Lagouvardia, his wife Maria and his children Nikiphoros, Anna and Katakali. The tomb of the founder is located in an arcosolium within the northern wall of the church. It is built in the domed cross - in - square architectural type. The elegant proportions of the monument and its brick walls consisting of blind arches, blind niches and half - columns are indicative of a Constantinopolitan influence. A second written inscription confirms the concurrence of its murals and its founding.

The only public Byzantine bath currently preserved in Thessaloniki is located on the outskirts of the Ano Poli, on Theotokopoulou Street. This is a small building of rectangular design, possibly dating back to the 13th century, and retains all the areas necessary for a bath: an antechamber, a tepid area, a warm area and a founding.

At the junction of Arrianou and Iasonidou streets, a short distance from the Arch of Galerius and the Rotunda, is the Byzantine church of Agios Panteleimon. The church, whose name is much newer, is identified with the catholicon of the monastery of Theotokos Peribleptos, also known as the monastery of Mr. Isaac, by its founder, Metropolitan Iakovos (1295 - 1314). It belongs to the complex cruciform type inscribed with a dome and a parapet, which ends in the east in two chapels. Few samples of the original fresco decoration are preserved in the chancel and the deaconry.

At the beginning of Olympou Street and close to the western walls lies the Church of Aghioi Apostoloi, once the catholicon of a monastery dedicated to the Virgin Mary, built by Patriarch Nephon (1310 - 1314) and his pupil, Abbot Pavlos. It is built in the complex five - domed tetrastyle cross - in - square type with an ambulatory. Of great interest is the structure of the external facades of the monument, with the ceramoplastic elements on its eastern side standing out. Its interior contains excellent mosaic decoration, characteristic of the final period of Palaeologan art.

In the Ano Poli, between Herodotou Street and Apostolou Pavlou Street, close to the eastern walls and within an enclosed yard lies the Church of Aghios Nikolaos Orphanos,which also served as the catholicon of a Byzantine monastery. It is built in the aisleless timber - roofed type with ambulatory, ending in the east with two chapels. Its exquisite mural decoration is one of most complete painting complexes preserved in Thessaloniki and is representative of Palaeologan art. Of the monastery complex, excluding the catholicon, only ruins of its entrance survive on Herodotou Street.

Above Olympiados Street, on the outskirts of the Ano Poli, at the junction of Tsamadou and Oedipoda Street, close the NW walls, lies the Church of Aghia Ekaterini, which once served as the catholicon of a Byzantine monastery. It dates back to the late 13th - early 14th century. It is built in the complex tetrastyle cross - in - square type with five domes and an ambulatory terminating in two chapels at the east end. Its elegant proportions and the structure of its facades, with recessed niches and arches, ceramic half - columns and ceramoplastic decoration, make this monument an excellent example of Palaeologan architecture. Its mural decoration, although surviving in fragments, follows the painting tradition of the early Palaeologan Renaissance.

At the junction of Egnatias and Paleon Patron Germanou Street lies the small church dedicated to the Saviour. It was built in 1340, possibly as a sepulchral chapel to a Byzantine monastery, and was originally dedicated to the Virgin Mary. It was built as a tetraconch inscribed in a square plan. The western conch was demolished in 1936 in order to add a narthex. The mural decoration in its interior dates back to 1350 - 1370 and is part of the Palaeologan tradition

Immediately outside the walls of the Acropolis, on Acropoleos Street, lies the Patriarchal and stauropegic Vlatadon monastery, the only Byzantine monastery still holding services in the city. It was founded between 1351 and 1371 by the monk Dorotheus Vlatis, a pupil of Gregory Palamas, and subsequently Metropolite of Thessaloniki. Of the original complex, only the catholicon survives, built in the cross - in - square type with an ambulatory ending in chapels. The mural decoration in its interior dates between 1360 and 1380. The church was initially dedicated to Christ Pantokrator and today honours Metamorphosis of Sotiros.

On Olympiados Street, at its junction with Profiti Elia Street, on a naturally rocky elevation, lies the imposing Church of Profitis Ilias. It is unique in Thessaloniki in terms of its architectural type : a tetrastyle cross - in - square trincoch with a narthex (lite) and an ambulatory terminating in two chapels. The Church was dedicated to Christ and served as the catholicon of the Akapniou Monastery. Of its iconographic decoration, only the portrayal of the Infanticide, representative of the final period of Palaeologan painting, survives in the narthex.

Admire the sculptures and statues of the city of Thessaloniki from the Archaic, Classic and Roman era. In a special section of the museum, there are treasures discovered in Vergina in 1978 and in Derveni in 1984.

The Byzantine Museum of Thessaloniki was established in order to become a center of conservation, research and study of the evidence of the Byzantine culture preserved in Macedonia and particularly in Thessaloniki, the city that was the most important center after Istanbul, in the European part of the Byzantine Empire. It is worth discovering the collections of sculptures, fresco paintings, mosaics, pictures and inscriptions from the Byzantine era.

The Thessaloniki Cinema Museum started when the city of Thessaloniki, in 1997, became the "Cultural Capital of Europe".
This initiative coincided with the global celebration of the 100 years of the Cinema. The Thessaloniki Cinema Museum, operating under the supervision of the Greek Ministry of Culture, is an independent part of the Thessaloniki International Film Festival. It aims at gathering, preserving and presenting the cinema life in Greece in a museum. (Port - Warehouse A', Thessaloniki)

The important activities of the Museum of Photography of Thessaloniki includes the holding of exhibitions (50 every year at the Museum of Photography of Thessaloniki and other halls) with the aim of promoting the Greek and also international photography, and presenting the various uses and approaches of photography.
The exhibitions are divided in exhibition cycles: "Glances at the City", "Great Creators", "Greek immigrants" "The four elements of nature and the human" etc. (Port - Warehouse A', Thessaloniki)