The Cathedral of St Demetrius (1194-97) is a royal church, built to the order of Grand Prince Vsevolod III. It is cubic in form, with three internal naves and a helmet dome. The cathedral is one-domed and four-pillared. Originally it was surrounded by galleries with towers that connected it to the prince's palace. They were demolished during the restoration in the 19th century.
The church is famous for its white-stone carvings - its walls are decorated with ca. 600 reliefs, depicting saints, mythical and real animals. Most of the reliefs are preserved in their original form, some have been replaced during the restoration of the 19th century. Out of the internal decoration a few fragments of frescoes of the 12th century have survived, particularly fragments of the Last Judgement composition. Currently, the cathedral is a part of the Vladimir-Suzdal open-air museum.
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.