Mulfra Quoit is a Neolithic dolmen in the county of Cornwall in England. It stands on Mulfra Hill to the north of the hamlet of Mulfra.
Mulfra Quoit is similar to Chûn Quoit five kilometers away. The quoit has three 1.7m-high support stones, arranged in a U-shape 3.0m long and 1.7m wide, and open on one side. The capstone, which has slipped down, measures 3.2m by 3.0m, and is almost square; it has a weight of 5 tonnes. Since some of the stones that formed the chamber are missing, it is difficult to get an idea of its original form, but it is possible that four pillars supported the capstone slab as with Chûn Quoit. On the other hand, the capstone has a central bulge on its underside, which would give the stone a stable position on the existing three pillars. Mulfra Quoit was apparently covered by a mound, the remnants of which are still present.
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.