The first defensive fortifications in Thessaloniki began shortly after its foundation, in the 3rd century BC. During the Roman period, a wall was built to repel raids, which was strengthened and completed by the 5th AD. during the reign of Theodosius the Great. The final construction, an exceptional fortification complex of walls, towers, and gates, was to protect the city from numerous attacks over the centuries. Part of this wall, the so-called "Castles" of Thessaloniki, is preserved today in half of the almost 8 km long original construction.
The city was fortified with a wall bordering three main points and in the Ottoman years, where the last additions were made in the 15th century, it looked like a huge fortress: The White Tower with the Tower of Vardar covered the sea zone and the walls from these two Towers reached as far as the Acropolis of Thessaloniki and the Eptapyrgio, where the circular Triangle Tower dominated (and still dominates).
The route of the remaining walls transports visitors from the city center to the Acropolis, where one, will be rewarded by the view of the whole of Thessaloniki and the sea horizon. The walls, which reached a height of 10-12 meters, are located very close to great and popular sights, especially in Ano Poli and below the Acropolis with the historic Eptapyrgio.