Mirabel, Spain
15th century
Zarza la Mayor, Spain
13th century
Gaibiel, Spain
12th century
Cáceres, Spain
15th century
Alcuetas, Spain
15th century
Arcos de Jalón, Spain
14th century
Villavellid, Spain
15th century
Alcaucín, Spain
10th century AD
Lora del Río, Spain
888-921 AD
Espelúy, Spain
13th century
Jaén, Spain
10th century AD
Medina de las Torres, Spain
14th century
Montemolín, Spain
12th century
Portezuelo, Spain
c. 1150
Cea, Spain
15th century
Mazuelo de Muñó, Spain
14th century
Valle de Valdebezana, Spain
14th century
Hornillos de Cerrato, Spain
15th century
Ciria, Spain
9th century AD
Ubrique, Spain
13th century
The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.