Cairns Castle is a ruined keep, dating from the 15th century. The Crichtons inherited the castle through marriage of the heiress of the castle who was the granddaughter of William de Carnys the original owner.
The castle has an adjoining wing. It has a vaulted basement, a kitchen on the ground floor, and a hall above. All floors were reached by a turnpike stair in the corner between the main block and the wing. There were at least three storeys. The kitchen fireplace was converted into an entrance. The entrance tower to the east no longer exists.
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.