The Anastasian Wall (Greek: , ; ) or the Long Walls of Thrace (Greek: , ; Turkish: Uzun Duvar) or simply Long Wall / Macron Teichos () is an ancient stone and turf fortification located west of Constantinople, built by the Eastern Roman Empire during the late 5th century.
Originally some long, it stretches from Evcik ðskelesi in ÃÂatalca at the Black Sea coast across the Thracian peninsula to the coast of the Sea of Marmara at west of Silivri (ancient Selymbria). It ran from north to south through the locations what are today Karacaköy, Gümüà Âpñnar, Pñnarca, Kurfallñ, Fener, Alipaà Âa Neighborhood and Silivri Altñnorak. Remains of the wall are visible in Gümüà Âpñnar junction in Karacaköy, Hisartepe in Yalñköy, Pñnarca in ðhsaniye and Kurfallñ village. The wall was part of an additional outer defense system for Constantinople, capital of the Eastern Roman Empire and probably continued in use until the 7th century.
The wall was named after the Emperor Anastasius I (). However, there is evidence that the fortification already existed in 469 during the reign of Leo I () and in 478 in the era of Zeno (), and it was maintained and renewed by Anastasius in the time from 507 to 512. The wall had a thickness of and a height over . It was built complete with towers, gates, forts, ditches and a military way to protect Constantinople from invasions from the west by Huns, Slavs and Bulgars. A rectangular castrum with dimensions of by existed also in the central section of the wall.
It is known that the wall had only a limited effectiveness, and various groups attacking Constantinople penetrated it many times, because the fortification's length made it difficult to defend the wall completely by a limited garrison, and also because the wall was not sufficiently strong due to its hasty construction.
The wall fell into ruin after it was abandoned in the 7th century because of the difficulty of keeping it manned and repaired. Over the centuries, the stone of more than half of the total length was reused in other local buildings. It is best preserved in the woodlands of the northern sector.