These are the ruins of the Land walls of Constantinople located in modern Istanbul (Turkey). They are over 1500 years old and for more than 1000 years they protected the capital of the Eastern Roman empire and one of the greatest cities of both the Antique and Medieval worlds. It is impossible to fully describe their history in a single paragraph. Throughout the ages they have withstood numerous sieges by armies of the Sassanid Persia from the territory of modern Iran as well as by Avars from the Balkans and Slavs from Bulgaria and Rus. The Arab armies of the first Jihad which swept across Europe, Africa and Asia were stopped and defeated beneath these walls. Their might impressed visitors from all corners of the world including Vikings from Norway such as Harald Hardrada, French and Norman leaders of the first crusade as well as countless pilgrims and ambassadors from regions as diverse as Spain, Ethiopia, Armenia, Scotland, Poland, Khazaria (where Judaism was adopted as the official state’s religion), Syria, Persia, India and even China. Today their abandoned ruins are covered with flags of Turkey and numerous commemorative plaques recall how they were conquered by the Ottomans nearly 1100 years after they were built. In essence they are made to serve as a monument for the Ottoman military glory and feature in numerous films about the siege of Constantinople in 1453. To be honest I could never understand such glorification of conquest, rape and plunder, Ottoman Empire was a fascinating state with intriguing culture and history but the fact that conquest, invasion and domination were so important in its identity never appealed to me. I would very much prefer to associate these walls with the heroism of the defenders and the security which they granted to the inhabitants of Constantinople for so many centuries. Lastly, they are in a way a burial monument of the last Byzantine Emperor, Constantine XI who died defending them and his body was never found. There are no other burial monuments of Byzantine Emperors because the 900 year old church of the Holy Apostles when they were buried since the time of emperor Justinian was deliberately erased to the ground by the Ottomans so these walls just have to do.
PS. I did not mention the fourth crusade here because the crusaders who sacked the city in 1204 and plundered its wealth massacring most of the inhabitants made a breach in the sea walls and not the land walls of the city.