La Platte Mare is a simple megalithic chamber with a single capstone dating back to the Chalcolithic or Early Bronze Age (2500 - 1800 BC). Early drawings show that some stones have been disturbed. Traces of a surrounding circle of stones 5m in diameter are no longer visible. One stone has a curved row of 12 cup marks though only 7 are visible above ground. A few metres away are the remains of another possible cist or chamber.
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.