Fitero, Spain
1141
Escorca, Spain
13th century
Yesa, Spain
842 AD
A Capela, Spain
10th century AD
Soria, Spain
12th century
Villaviciosa, Spain
1200-1226
Burgos, Spain
1442
Sobrado, Spain
952 AD
Nogueira de Ramuín, Spain
921 AD
Granada, Spain
16th century
Cuacos de Yuste, Spain
1402
Lerma, Spain
1604
Burgos, Spain
1187
Calera de León, Spain
13th century
Ayegui, Spain
10th century AD
Monforte de Lemos, Spain
10th century AD
Ávila, Spain
1482-1493
Poio, Spain
17th century
Granada, Spain
1506
San Cristovo de Cea, Spain
1137-1141
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.