Burroughston Broch is an Iron Age structure located on the island of Shapinsay. Excavated in the mid 19th century, Burroughston Broch is still well-preserved. The drystone walls are up to four metres thick in some parts and there is a complete chamber intact off the entrance passage. Some remains of stone fittings are evident in the interior.
The walls of Burroughston Broch have an external diameter of around 18 metres, and an internal diameter of around 10 metres. From the outside, the building appears as a grassy mound, and little of the outer wall is exposed.
The entrance passage is on the east side, and is about 4 metres long, 1.2 metres wide and 1.8 metres high. There is an elongated guard room opening from the left side of the passage. Inside the broch, the outer face of the upper gallery is still visible, and traces of an opening to the upper gallery are still apparent. A deep well is present in the broch floor: the upper part being dry stone masonry, the lower being cut into the rock.
In the sloping area in front of the broch entrance are traces of 'out-buildings' now covered with turf. A wall, ditch and rampart, which probably once encircled the broch, are still evident around the structure.
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.