Innisidgen is the site of two Bronze Age entrance graves on the island of St Mary's in the Isles of Scilly. The two burial monuments, (Upper and Lower Innisidgen) lie on a steep slope of Innisidgen Hill overlooking Crow Sound with a view towards the Eastern Isles.
The Isles of Scilly were originally settled during the Neolithic era, circa 2500 BC. Burial monuments on the islands range in date from the later Neolithic period to the Middle Bronze Age (c.2500-1000 BC). Entrance graves are distinguished by their burial chamber, typically constructed with edge-set slabs, coursed rubble walling or both, and roofed by large covering slabs. The chamber is usually accessible through an opening in the mound's stone outer edge. Excavations of entrance graves have generally uncovered cremation urns, pottery fragments and cremated and unburnt human bones.
The two entrance graves at Innisidgen Hill were built during the Bronze Age. At the time of construction, the burial chambers overlooked a coastal inlet, later known as Crow Sound. During the prehistoric era, this site would have encompassed a wide valley of fields enclosed by stone walls. The remains of a prehistoric field system are located on the northern slope of Innisidgen hill next to the entrance graves, discernible as earth and piles of rubble. No artefacts or human remains were found when both graves were first excavated in 1854.
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.