The famous Kvitsøy Stone Cross was erected between 800–1050 AD. Some say it was put there by English missionaries in the 900s while others claim it was raised by Erling Skjalgsson and Olav Haraldsson, Viking chiefs, in 1016. There are a number of large stone crosses along the west coast of the Norway. Kvitsøy is first mentioned in the Snorre Saga, where Snorre records a truce being made between King Olaf II of Norway later to be known as St. Olav (Hellige Olav) and Erling Sjalgsson, under the stone cross.
References: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.