Edin's Hall Broch is a 2nd-century broch near Duns in the Borders of Scotland. It is one of the most southerly broch survivals, which are more typically associated with Northern Scotland.
The broch stands in the northwest corner an Iron Age hillfort which presumably pre-dates the broch. The hillfort consists of a double rampart and ditches, enclosing an oval area some 135 metres by 75 metres. A large circular structure (roundhouse) in the centre of the fort, close to the broch, may have been the most important building before the broch's construction.
It is assumed that the hillfort dates to the pre-Roman Iron Age. The date of the broch is uncertain but it has been speculated that it was built between the two main periods of Roman occupation in Scotland: some time in the 2nd century AD. Excavations at Torwoodlee Broch, also in the Scottish Borders, has shown that it was built and demolished during this period.
Within the hillfort is an array of stone footings marking the positions of houses and other structures. Some of the houses overlie the defences – indicating that they are later than hillfort and may be later than the broch as well.
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.