Adelsö, Sweden
ca. 750 AD
Bornholm, Denmark
750 AD
Kleindannewerk, Germany
500 AD
Eastern Settlement, Greenland
985 AD
Ekerö, Sweden
ca. 100-1520 AD
Kerteminde, Denmark
c. 925 AD
Borre, Norway
600-900 AD
Borgsum, Germany
9-10th century AD
Qassiarsuk, Greenland
10th century
Tønsberg, Norway
834 AD
Sylt, Germany
0 AD
Veliky Novgorod, Russia
9th century AD
Nøtterøy, Norway
500-1000 AD
Logstor, Denmark
10th century
Mörbylånga, Sweden
800-1000 AD
Kvitsøy, Norway
800 - 1050 AD
Lejre, Denmark
550 - 1000 AD
Morbylånga, Sweden
1000 BC-1000 AD
Mörbylånga, Öland, Sweden
ca. 950-1000 AD
Suðuroyar, Faroe Islands
970 AD
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.