Ardgowan Castle is located in the grounds of Ardgowan House near Inverkip. In 1306, Inverkip was besieged by supporters of Robert Bruce, led by Robert Boyd of Cunningham. In 1403, King Robert III granted the lands of Ardgowan to his natural son, Sir John Stewart. The castle is dated to the late 15th century.
In 1667 Archibald Stewart was created a baronet. The 3rd baronet married, in 1730, Helen Houston, heiress of the Shaws of Greenock. Their son Sir John Shaw-Stewart, 4th Baronet, commissioned a design for a new house from the architect Hugh Cairncross. Construction began in 1797, and was completed around 1801, after which the old castle was abandoned. The ruin was consolidated and repaired in 1936.
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.