The Mound of Down is an ancient monument which gives County Down its name. Originally the home of Celtair - Rath Celtair - this became a stronghold for the Dál Fiatach, a powerful army who once owned the Isle of Man. It is a good example of an Iron Age defensive earthwork in the middle of which a Norman Motte and Bailey was built by John de Courcy after his defeat of Rory Mac Donlevy in 1177.
Originally on the shores of Strangford Lough this site was an excellent military base. The land around has been reclaimed since the 1700s. Today the site is an impressive motte and bailey style fort which was abandoned before completion.
From the top of the incomplete mound you have an excellent view over Down Cathedral and Inch Abbey. In the distance are the Mourne Mountains. During the summer the site is left to grow as a wildlflower meadow.
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.