The Theodosian Walls, a monumental defense system constructed during the reign of Emperor Theodosius II in the 5th century, were integral to protecting Constantinople for over a millennium. Stretching from the Sea of Marmara to the Golden Horn, these fortifications included a double wall, towers, and a moat, with some sections standing even today, albeit in ruins. These walls withstood numerous sieges, most notably by Attila the Hun and later by the Ottomans in 1453. Today, remnants of these walls, such as those near Tekfur Saray, offer a fascinating glimpse into Byzantine engineering. Along with the nearby structures like the Golden Gate, the Theodosian Walls remain a testament to the city's strategic and architectural significance​