Cong, Ireland
1138
Sligo, Ireland
1253
Sligo, Ireland
1809
Donegal, Ireland
1474
Letterkenny, Ireland
1890-1900
Newport, Ireland
1470
Sligo, Ireland
1874
Killala, Ireland
c. 1441
Strade, Ireland
c. 1240
Castlebar, Ireland
9th century AD
Raphoe, Ireland
12th century
Dromahair, Ireland
1508
Ballintober, Ireland
1216
Ballymote, Ireland
1507
Clare Island, Ireland
12th century
Inishmurray, Ireland
6th century AD
Inishowen, Ireland
6th century AD
Falcarragh, Ireland
6th century AD
Killala, Ireland
15th century
Ballina, Ireland
1834
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.