Theodosius II’s land walls are among the most fascinating Byzantine remains in Turkey. Well-preserved remnants can still be found along the whole of their 6.5km length, though purists (and UNESCO) decry the fact that much of the recent work done on the walls looks like new-build rather than restoration.
The land walls were named after Theodosius II, and construction started in 413 AD. Stretching from the Marmara to Tekfur Saray, 2km further out than the previous walls of Constantine, they were built to accommodate the city’s expanding population. All citizens, regardless of rank, were required to help in the rebuilding following their collapse in the earthquake of 447 AD, in the light of the imminent threat of attack by Attila the Hun. The completed construction consisted of the original wall, 5m thick and 12m high, plus an outer wall of 2m by 8.5m, and a 20m-wide moat, all of which proved sufficient to repel Atilla’s assault.
Walking along the walls takes a little over two hours, though a full day allows time to enjoy it, and the adjacent sites, fully. Most of the outer wall and its 96 towers are still standing; access is restricted on some of the restored sections, though elsewhere there’s the chance to scramble along the crumbling edifice. As there are still plenty of run-down slums in this area, it’s best avoided at night (especially Topkapı).
The three principal sights can also be visited independently. The Yedikule fortifications, towards the southern terminus of the walls, are best reached by walking up from the suburban train station at Yedikule. The Kariye Museum, a former Byzantine church containing some of the best-preserved mosaics and frescoes in the world, just in from Edirnekapı and around 750m north of the Golden Horn, is easily accessed from the Ulubatlı M1 metro stop or the Pazartekke T1 tramstop, the Mihrimah Camii likewise – or take #28, #38E or #336E bus from Eminönü to Edirnekapı.