Lummelunda, Sweden
17th century
Österbybruk, Sweden
16th century
Fagersta, Sweden
1681
Filipstad, Sweden
1590
Nora, Sweden
19th century
Sundsvall, Sweden
1673
Forsbacka, Sweden
1640
Pajala, Sweden
1644
Hallstahammar, Sweden
1628
Motjärnshyttan, Sweden
1643
Tierp, Sweden
1643
Knutby, Sweden
1683
Söderfors, Sweden
1676
Vattholma, Sweden
1545
Bäckefors, Sweden
1767
Örebro, Sweden
1558
Vikmanshyttan, Sweden
1628
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.