The Walls of Thessaloniki

The walls of Thessaloniki are the great land and sea fortifications that ringed the Byzantine city, a circuit of close to four kilometres of stone and brick. They stand in their present form from the late fourth to the middle of the fifth century, raised on the line of an earlier late-Roman wall. The defence climbed from the shore to the crown of the hill, where the acropolis and the Eptapyrgio held the high ground. Much of the lower and seaward line came down in the late eighteen-hundreds, yet the northern stretch above the old town still rises to its full height. Trace the circuit from the sea to the citadel and read the defence of the Byzantine city with My Greece Tours.

A walk of the walls rewards the climb from the seafront to the ramparts rather than a single photograph from the road. The stone carries the record of siege and repair, the inscriptions that name the men who built each stretch, and the towers that guard the corners of the line. The sections below cover what the walls are, when they were built, and how their alternating courses were laid. The later parts turn to the acropolis and the Eptapyrgio, to the demolition of the sea walls, and to how a walk from the White Tower up to the citadel folds into the guided Thessaloniki tours.

What are the walls of Thessaloniki?

The walls of Thessaloniki are the Byzantine land and sea fortifications of the city, a circuit of close to four kilometres. They enclose the lower town, the acropolis, and the inner citadel of the Eptapyrgio on the hill above.

The walls form a rough triangle that once climbed from the gulf to the summit of the hill and back down to the water. The line ran along the seafront on the south, up the eastern and western slopes, and across the high ground of the north, where it joined the acropolis. Their surviving height reaches between eight and ten metres, and the ramparts measure up to four and a half metres thick at the base. A wall walk ran along the top behind a parapet, linked by towers set at intervals down the whole length of the circuit.

The defence divided into the land walls and the sea walls, each built for a different threat. The land walls faced the plain to the north and east, the direction of the armies that marched on the city, and they carried the tallest towers and the deepest ditches. The sea walls ran low along the shore to guard the harbour and the beach from a fleet. The northern angle rose to the acropolis, a walled upper town within the circuit, and the Eptapyrgio held the highest corner as a fortress in its own right.

The walls rank among the essential sights of the city for the scale of what survives and the sweep of the view from the ramparts. They head most guides to things to do in Thessaloniki, a landmark that ties the modern streets to the medieval town. The line runs from the White Tower on the seafront, the lone survivor of the coastal defence, up through the lanes to the crest of the hill. A traveller can read the whole shape of the Byzantine city by walking the surviving stretch from the shore to the summit.

The walls carry a place on the UNESCO World Heritage List within the group of the Palaeochristian and Byzantine Monuments of Thessaloniki. The listing marks the fortifications as a record of Byzantine military building that held the empire’s second city through long centuries of siege. Their span across the hill, from the sea to the citadel, preserves the plan of a great medieval capital in a way few walls in the eastern Mediterranean still do.

When were the walls of Thessaloniki built?

The walls stand in their present form from the late fourth to the middle of the fifth century, raised on an earlier late-Roman circuit of the third century. Later emperors repaired and rebuilt stretches through the Byzantine centuries.

The first full circuit rose in the late third century, when the city walled itself against the raids of the Goths who pressed down from the north. That early wall reused the stone of older buildings and threw a defence around the Roman town on the gulf. It held against attacks that struck the region and set the line that the later walls would follow. Stretches of that third-century masonry survive within the fabric of the standing walls, built over and heightened by the works that came after.

The walls that stand today took their form between the late fourth and the mid fifth century, in a rebuilding that raised the circuit to its full height. The work belongs to the age when the city served as a seat of empire on the road between the western and eastern capitals. The builders followed the earlier line but lifted the ramparts higher and set a dense row of towers along the length. This is the wall that carried the city through the sieges that fill the history of Thessaloniki.

Inscriptions cut into the stone name the men who paid for and raised the walls, a record rare among the fortifications of the age. One long inscription set into the eastern wall credits a builder named Hormisdas with the construction of the circuit. Other blocks carry the monograms and the names of emperors and officials who repaired their stretches in later centuries. These carved lines let historians date the phases of the wall and read the chain of rebuilding across the Byzantine centuries.

The walls saw major repair under the Palaiologan emperors of the later Byzantine centuries, who rebuilt gates and towers against the threats of their age. The Anna Palaiologina gate on the western line carries the name of an empress from that work. The Eptapyrgio and the acropolis took part of their standing form in the same medieval campaigns. The circuit passed to Ottoman hands in the fifteenth century, and the new rulers held and patched the walls for another four hundred years.

How were the walls of Thessaloniki built?

The walls were built in the late-Roman manner, with courses of squared stone alternating with bands of flat brick. Square and triangular towers stand along the line, and the ramparts reach up to four and a half metres thick.

The masonry sets bands of ashlar, squared blocks of stone, between courses of thin red brick that run in level lines across the face. That alternation of stone and brick gives the wall its banded look and binds the fabric against the shock of an earthquake or a battering ram. The brick courses level the wall as it climbs and tie the stone together like the rungs of a ladder. The technique marks the standard late-Roman and early Byzantine way of raising a great defensive wall.

The standing walls rise between eight and ten and a half metres in the best-preserved stretches, and the base measures up to four and a half metres in thickness. A walkway ran along the top behind a battlemented parapet, wide enough for the defenders to move and fight. The height and the mass let the garrison command the ground below and hold the wall against a long siege. The scale of the surviving northern line shows the full ambition of the Byzantine defence.

Towers stand at set intervals along the whole circuit, square and round on much of the line and triangular where the builders wanted to deflect a ram. The triangular projections point outward like the prow of a ship and throw an attacker’s blows aside. Each tower rose above the wall walk and let the defenders shoot along the face of the curtain between them. Gates broke the line at the main roads, guarded by paired towers and set back within the wall for defence.

The same builders who raised the walls shaped the churches and the public works of the Byzantine city within them. The banded stone-and-brick technique of the ramparts returns in the Byzantine churches of Thessaloniki, a shared language of stone and brick across the medieval town. The wall, the church, and the cistern all drew on the workshops and the materials of one building tradition. A visitor who reads the masonry of the walls reads the hand behind the wider fabric of the city.

What are the acropolis and the Eptapyrgio?

The acropolis is the walled upper town at the northern crown of the circuit. The Eptapyrgio, or seven towers, is the inner citadel at its highest corner, a fortress within the fortress that guarded the summit.

The acropolis crowns the north of the walled city, a separate enceinte set within the greater circuit on the highest ground. Its walls climb the slope above Ano Poli, the Upper Town, and command the whole spread of the city down to the gulf. The upper town gave the garrison a stronghold to hold if the lower walls fell to a siege. Its ramparts carry the same banded masonry as the main line and stand today among the best-preserved parts of the whole defence.

The Eptapyrgio holds the highest corner of the acropolis, an inner citadel whose name means seven towers in Greek. The Ottomans knew it as the Yedi Kule, a translation of the same name, and they used it as a garrison and later as a prison. Its northern front joins the Byzantine wall, while its southern towers belong to Ottoman rebuilding of the fortress. A long inscription over the main gate records the medieval work that gave the citadel its standing shape.

The Trigonion tower marks the north-eastern angle of the circuit where the acropolis wall meets the main line. Known also as the Chain Tower for the band of stone that rings its top, it rose in the later Byzantine and Ottoman period as a broad artillery bastion. Its rounded mass replaced an older corner tower and was built to mount and withstand cannon. The platform at its foot gives one of the widest views over the city and the gulf on the whole walk.

The Tower of Manuel Palaiologos stands on the eastern acropolis wall and carries an inscription naming the emperor who raised it. Its stone records the Palaiologan campaign that strengthened the upper defences in the later Byzantine centuries. The tower joins the line of named towers and gates that let historians tie the fabric to the rulers who paid for it. Together the acropolis, the Eptapyrgio, and their towers form the strongest and best-kept quarter of the whole circuit.

Why were the sea walls of Thessaloniki demolished?

The sea walls and much of the lower land circuit were pulled down in the late eighteen-hundreds, when the Ottoman administration cleared the old defences to open the city to the harbour and to modern growth.

The walls lost their military use as artillery advanced and the growth of the city outran the medieval line. The Ottoman administration ordered the seaward wall taken down in the late eighteen-hundreds to open the shore for a new quay and a waterfront boulevard. The whole coastal defence came down along with the towers that had guarded the harbour, and the sea gate was lost. The one survivor of that seaward line is the White Tower, spared as a landmark at the eastern end of the shore.

The clearance took the lower land wall as well, on the eastern and western flanks near the sea, to free ground for the growing town. New avenues and blocks rose over the line the walls had held for a millennium and a half. The demolition opened the seafront that the city keeps today, the long promenade from the harbour to the tower. The trade of an old defence for a modern shore reshaped the face of the city on the gulf.

A great fire later swept the lower town and cleared the streets that the walls had once enclosed, which opened the way for a planned rebuilding of the centre. The new grid rose without the old ramparts to hem it, and the walls survived best where the fire and the builders did not reach. The high northern line above the Upper Town escaped both the demolition and the flames. That accident of geography left the standing walls concentrated on the hill rather than the shore.

The loss of the sea walls means a visitor reads the circuit today from the land side and the heights rather than the water. The surviving stretch runs from the eastern acropolis down the western slope, a long and near-continuous line above the old town. What came down is marked now by the course of the modern streets that follow the vanished wall. What stands gives a full picture of the Byzantine defence on the high ground, if not along the lost shore.

How do you walk the walls of Thessaloniki today?

A walk of the walls climbs from the White Tower on the seafront up through the Upper Town to the acropolis and the Eptapyrgio. The standing line above the old town runs for well over a kilometre of rampart.

The classic walk starts at the White Tower on the shore and climbs north through the streets toward the ramparts on the hill. The grade is steep in stretches as the route gains the height of the old town, and stout shoes and water reward the climb in the warm months. The line of the walls appears as the streets narrow into the lanes of the Upper Town near the top. From there the standing rampart runs almost unbroken along the crest to the acropolis and the citadel.

The best of the walk follows the wall through the Upper Town, where the Ottoman houses and the fountains survived the fire below. The lane hugs the outer face of the rampart for a long stretch, and towers and gates break the line as it climbs. A guided Thessaloniki walking tour draws out the phases of the stone and the inscriptions that a bare wall keeps quiet. The route reaches the Trigonion tower at the north-eastern angle, where the platform opens the widest view of the walk.

The high point of the walk gains the acropolis and the Eptapyrgio at the crown of the hill, the strongest quarter of the defence. From the citadel the whole city falls away to the gulf, with the churches and the Rotunda picked out among the roofs below. A descent by a different lane can take in the Rotunda and the Roman monuments of the centre on the way back to the shore. The loop from the sea to the summit and down reads the full height of the Byzantine city in one walk.

The walls fold cleanly into a day on foot through the old town for the traveller who plans the climb into the cooler hours. A route that opens at the seafront, climbs the walls to the acropolis, and turns down through the churches builds the medieval city in the right order, the shape a compact Thessaloniki itinerary tends to follow. Morning light or the late afternoon suits the ramparts best, when the low sun warms the stone and the view over the gulf clears. A guide ties the wall, the citadel, and the town below into one story rather than a scatter of stops.

Frequently Asked Questions

How long are the walls of Thessaloniki?

The full Byzantine circuit ran for close to four kilometres, enclosing the lower town, the acropolis, and the Eptapyrgio on the hill. Much of the lower and seaward line came down in the late eighteen-hundreds, so the surviving wall is shorter, yet a long and near-continuous stretch of well over a kilometre still stands above the Upper Town on the northern heights.

How old are the walls of Thessaloniki?

The walls stand in their present form from the late fourth to the middle of the fifth century, built on the line of an earlier late-Roman circuit of the third century. Later emperors repaired and rebuilt stretches through the Byzantine centuries, and the Ottomans held and patched the walls for another four hundred years after the fifteenth century.

What is the Eptapyrgio?

The Eptapyrgio, whose name means seven towers, is the inner citadel at the highest corner of the acropolis, a fortress set within the greater walled city. The Ottomans called it the Yedi Kule and used it as a garrison and later as a prison. Its northern front is Byzantine, while its southern towers belong to Ottoman rebuilding of the stronghold.

Are the walls of Thessaloniki a UNESCO World Heritage Site?

Yes. The walls carry a place on the UNESCO World Heritage List within the group of the Palaeochristian and Byzantine Monuments of Thessaloniki. The listing recognises the fortifications as an outstanding record of Byzantine military architecture, alongside the churches and the Rotunda that share the inscription across the old town. Their banded masonry and their span from the sea to the summit mark them among the great surviving city walls of the medieval Greek world.

Can you walk along the walls of Thessaloniki?

A visitor can walk the outer face of the walls for a long stretch through the Upper Town, where the lane follows the rampart from tower to tower up to the acropolis. The wall walk along the top is not open as a continuous path, so the route runs beside the ramparts on the street rather than on the parapet. The climb from the White Tower to the citadel makes the classic line.

What is the Trigonion Tower?

The Trigonion, also called the Chain Tower, is the broad round bastion at the north-eastern angle where the acropolis wall meets the main circuit. It rose in the later Byzantine and Ottoman period to mount and withstand cannon, replacing an older corner tower. The platform at its foot gives one of the widest views over the city and the gulf on the whole walk of the walls.