Archidona, Spain
9th century AD
Badajoz, Spain
1551
Roquetas de Mar, Spain
16th century
La Calahorra, Spain
1509-1512
Cuéllar, Spain
13th century
Iznájar, Spain
8th century AD
Buitrago del Lozoya, Spain
15th century
Montefrío, Spain
15th century
Alcaudete, Spain
13th century
La Iruela, Spain
11th century
Castro Caldelas, Spain
14th century
Pedraza, Spain
13th century
Carmona, Spain
13th century
Cartagena, Spain
1777
Biar, Spain
12th century
Córdoba, Spain
1406-1408
Peñafiel, Spain
10th century
Sanlúcar de Barrameda, Spain
15th century
Alcalá de los Gazules, Spain
12th century
Monterrei, Spain
12th 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.