The Callanish III stone circle is one of many megalithic structures around the better-known (and larger) Callanis Stones (I) on the west coast of the isle of Lewis. The stone circle consists of two concentric ellipses. The outer ring measures about 13.7 by 13.1 metres. It contains 13 stones, of which eight are still standing and five have fallen. The inner ring is a pronounced oval measuring 10.5 by 6.6 metres. Only four stones remain in the inner circle, the tallest of which measures 2.1 metres. There is no sign of a central mound or cairn.
It is just a few hundred metres from the Callanish II stone circle.
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.