City Walls
The city of Constantinople was surrounded by fortification walls in order to protect the city from their enemies.
In total, there were roughly 21km city walls around the city.
The city was surrounded with different type of walls built during different eras both from sea and land side.
Today some parts of the city walls from 413AD, the period of the Roman emperor Theodosious II, remain. Through the city walls of Constantinople there were roughly 81 gates and 96 towers for accessing the city some of which still survive today.
One of the towers is Yedikule Tower which is like an open-air museum today. It was used during the Ottoman era as a prison. Even one of the sultans were imprisoned and executed here! Various sieges and earthquakes have contributed to the decay of the walls.
Since the 80s, there has been a restoration program to renovate the walls.