Belcastel, France
9th century AD
Sévérac-d'Aveyron, France
13th century
Najac, France
1253
Bournazel, France
16th century
Gissac, France
15th century
Brousse-le-Château, France
10th century
Saint-Izaire, France
14th century
Rivière-sur-Tarn, France
12th century
Lacroix-Barrez, France
12th century
Salles-la-Source, France
13th century
Espalion, France
11th century
Alrance, France
15th century
Coupiac, France
15th century
Viala-du-Pas-de-Jaux, France
1430
Camjac, France
1180
Saint-Beauzély, France
12th century
Vézins-de-Lévézou, France
1120
Saint-Rome-de-Cernon, France
14th century
Lugan, France
1180
Rebourguil, France
13th 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.