The Abbey of the Santo Spirito (Holy Spirit), built by the Norman Count Ruggero and his wife Queen Adelasia in 1092–1098, was consecrated in 1153. It has been greatly altered in subsequent centuries. The original outlines are still identifiable to the rear, where its characteristic massive jutting apses can be seen. These are separated by flat pilasters and connected by a series of small arches. The left-hand entrance has an ogival portal from the 13th century. The lunette once contained a figure of Christ Blessing, which was eventually moved inside the Abbey. Notable are the rectangular nave and wooden-beamed ceiling. The walls and the apses have frescoes attributed to the 14th century. The vault of the apse shows a 17th-century figure of Christ Pantocrator.
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.