Just north of the ridge summit of Cefn Bryn, there is a neolithic burial ground, known as 'Arthur's Stone' (Maen Ceti). Its name comes from a legend that the ancient British King Arthur threw a large stone from Llanelli which landed on this spot.
It is believed that during the Bronze Age Cefn Bryn was used extensively for ceremonies and rituals. Beneath the bracken on the hill over sixty cairns have been discovered. Most of these are likely to be no more than collections of stones cleared by local farmers; but just north-west of Arthur's Stone three prominent cairns have been excavated that prove their ancient role - the largest being Great Cairn, a circular heap of stones above a central grave.
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.