San Miguel is a Roman Catholic church in Córdoba, Andalusia, southern Spain. It is one of the twelve churches built by order of King Ferdinand III of Castile in the city after its conquest in the early 13th century. It was declared a monument of national interest in 1931.
It is an example of transition from the Romanesque to Gothic architecture, although the interior was largely renewed in 1749. It has a nearly square plan, with a nave and two aisles without a transept, a with polygonal apses; the nave has a coffered ceiling.
The main altar, in marble, was built in the 18th century. A side entrance has a horseshoe arch, perhaps dating to the Caliphate age.
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.