Tsikhisdziri is home to an archaeological site and ruins of a Late Antique fortified town, which is identified with the Roman-built city-fortress of Petra.
Petra, founded at the behest of the emperor Justinian I in 535 and, after a series of battles for the possession of that city during the Lazic War with Sasanid Iran, was demolished by the Romans themselves to prevent it again becoming the enemy's target in 551. Later, the locale continued to be home to a stronghold of some importance.
The Tsikhisdziri fortress was situated on two coastal hills, connected to each other through double walls. On the territory of the citadel, the area of which totals around 1.5 h, are the ruins of a 6th-century three-nave basilica with the dimensions of 33X17.80 m, with narthex, projecting apse, and floor mosaic, and remains of two other churches, one from the early Christian period and the other dated to the High Middle Ages. Close to the basilica is a 6th-century bath and a water cistern. North to the citadel are the ruins of an urban settlement and hundreds of burials. These structures date from the Late Antiquity to the Middle Ages.
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.