Pontoise Cathedral, raised to the status of cathedral in 1966 when the Diocese of Pontoise was created, is dedicated to Saint Maclovius (Maclou). Construction began in the 12th century on the site of an ancient chapel of Saint Eustace and the building was enlarged and completed in the 15th and 16th centuries. Thus the central and eastern parts of the cathedral are 12th century, while the tower and the central portal are in the Flamboyant style. There are Renaissance additions flanking the central structure, and a north portal of the same period.
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.