The Besleti Bridge, also known as the Queen Tamar Bridge, is a medieval arched stone bridge at Sukhumi, Georgia’s breakaway republic of Abkhazia. It dates back to the late 12th century. Thirty-five meters in overall length and eight meters high, this single-arch bridge is one of the most illustrative examples of the medieval bridge design popular during the reign of Tamar of Georgia (r. 1184-1213) who is traditionally credited to have commissioned the construction of the Beslet bridge.
In the vicinity of the bridge are the ruins of medieval combat towers, a testimony to strategic importance of the locale.
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.