The Katskhi pillar is a natural limestone monolith. It is approximately 40 metres high, and overlooks the small river valley of Katskhura.
The rock, with visible church ruins on a top surface measuring c. 150 m2, has been venerated by locals as the Pillar of Life and a symbol of the True Cross, and has become surrounded by legends. It remained unclimbed by researchers and unsurveyed until 1944 and was more systematically studied from 1999 to 2009. These studies determined the ruins were of an early medieval hermitage dating from the 9th or 10th century. A Georgian inscription paleographically dated to the 13th century suggests that the hermitage was still extant at that time. Religious activity associated with the pillar was revived in the 1990s and the monastery building had been restored.
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.