Martvili Monastery sits upon the highest hill in the vicinity and was of strategic importance. The site upon the hill where the monastery stands today was used in ancient times as a pagan cultural center and was a sacred site. There once stood an ancient and enormous oak tree that was worshipped as an idol of fertility and prosperity. Infants were once sacrificed here as well. After the conversion of the native population to Christianity, the ancient tree was cut down so as not to worship it anymore. A church was originally constructed in the late 7th century upon the roots of the old oak tree and was named in honor of Saint Andrew who preached Christianity and converted the pagans across the Samegrelo region.
The main Martvili-Chkondidi Cathedral (Chkoni translates to 'oak') was reconstructed in the 10th century after invasions that destroyed the prior church. Preserved in the church are frescoes of the 14th to 17th centuries.
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.