The Wall in Istanbul - build in 413 under the rule of Theodosius II

A walk along the entire Land Wall from The Golden Horn to The Marmara Sea

The Land Wall stretches 6 km. Another "Sea Wall" (14 km) surrounded the coastline of the peninsular. The Walls protected Konstantinopel from numerous attacks and were only conquered twice - in 1204 (the Crusaders) and in 1453 (the Ottomans).