Priaranza del Bierzo, Spain
9th century AD
San Felices de los Gallegos, Spain
13th century
Caracena, Spain
1491
Ucero, Spain
12th century
Mombeltrán, Spain
1462-1474
Poza de la Sal, Spain
9th century AD
Tiedra, Spain
13th century
San Cebrian de Castro, Spain
12th century
Monleón, Spain
13th century
Losacino, Spain
12th century
Coruña del Conde, Spain
10th century
San Esteban de Gormaz, Spain
10th century
Monzón de Campos, Spain
14th century
Monteagudo de las Vicarías, Spain
15th century
Almenar de Soria, Spain
15th century
Santa Gadea del Cid, Spain
11th century
Fuentidueña, Spain
12th century
Magaña, Spain
15th century
Yanguas, Spain
14th century
Mironcillo, Spain
1490
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.