Carrickabraghy Castle (Caisleán Charraig Bhrachaí) on a rocky outcrop at the north-western extremity of the Isle of Doagh in the north of Inishowen, a peninsula on the north coast of County Donegal, Ireland.
From the 9th to the 13th century Inishowen was politically divided into three 'tuatha' or districts. These were known as Aileach in the south, Bredach to the east and Carraig Bhrachai to the west. The Lords of Carraig Bhrachai ruled from the town-land of Carrickabraghy, the area where the Castle now stands. They were one of the most important families in Inishowen.
Carraig Bhrachai is not mentioned again in the history books until 1600. The present remains of the castle are thought to have been built around this time. The O Dochartaigh Clan had risen into power in Inishowen and the Chief of the clan and Lord of Inishowen was Sean Og O Dochartaigh. The English invasion of Ireland was well underway, and to protect his livestock and supplies from English raids, Sean Og decided the best place to store them was on The Isle of Doagh.
Around 1665 Carrickabraghy Castle was abandoned, and began to decline for several centuries.
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.