Alicante, Spain
1613-1662
Ávila, Spain
1091
Ibiza, Spain
1235
Pamplona, Spain
1394-1501
Mérida, Spain
1479
Ourense, Spain
1220
Lugo, Spain
1129
Cartagena, Spain
13th century
San Sebastián, Spain
1888-1897
Astorga, Spain
1471
Zamora, Spain
1151-1174
Jerez de la Frontera, Spain
17th century
Ciutadella de Menorca, Spain
1300-1362
Vitoria-Gasteiz, Spain
13th century
Santander, Spain
12th century
Tui, Spain
1120-1225
Baeza, Spain
16th century
Plasencia, Spain
13th century
Palencia, Spain
1172
Jaén, Spain
16th 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.