The Russian Old-Believers (starovery) have kept their religious rituals unchanged for more than 1000 years. Today, there are 11 starover congregations with approximately 15 000 members in Estonia. A museum situated in Kolkja village on the coast of Lake Peipsi displays traditional clothes, crafts, tools, household items, and religious items of the Old-Believers.
Reference: Kolkja Museum of Old Believers
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.