Defensive walls of Gorgan
The Great Wall of Gorgan begins alongside the Caspian Sea in the Gomishan area and continues to the Galidagh Mountains, north-east of Kalaleh (Golestan region). Its antiquity is not exactly known since the name of the Medes, Achaemenids, Parthians and Sassanids stands out in the works of the researchers but perhaps the date of its construction can be vaguely placed between the years 429 and 615 AD. C.
Most historians believe that this wall was built by the Sassanid king Anushirvan, while others believe that this historic building was started by Yazdegard I and completed by Anushirvan.
The Gorgan wall, which stretches for almost 200 km, after the Chinese wall and the Berlin wall in Germany, is the third largest defensive historic brick wall in the world and today only a small part of it remains.
Regarding the materials used in the construction of the walls of Gorgan which are also called by other names such as: great walls of Alexander, red walls and red snake, the opinions are varied: it is believed that stone and lead, brick were used and lime, brick and plaster, stone and plaster or marble and terracotta brick and are believed to have been built over a 90-year period.