Πύργος Αλύσεως

The Chain Tower (Πύργος Αλύσεως) is a surviving Byzantine fortification tower on the Thessaloniki waterfront, built as part of the city's medieval harbor defense. Its name derives from an iron chain that could be stretched across the harbor mouth to block enemy vessels — a defensive technique common to Byzantine port cities, most famously employed at Constantinople. Today it stands as one of the few intact remnants of the city's Byzantine and Ottoman-era walls, open to visitors most days until 19:00.