Alcalá de Henares, Spain
1497 -1515
Guadix, Spain
16th century
Tudela, Spain
1168
Almería, Spain
1524-1562
Castelló de la Plana, Spain
1939
Badajoz, Spain
13th century
Burgo de Osma, Spain
1232
Mondoñedo, Spain
1219
Ciudad Rodrigo, Spain
12th century
Coria, Spain
1498
Orihuela, Spain
1281
Segorbe, Spain
1246
Huelva, Spain
1775
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.