The Church of Saint Demetrius of Thessaloniki in Veliko Tarnovo, Bulgaria, a medieval Bulgarian Orthodox church, was part of a monastery and played a role in the anti-Byzantine Uprising of Asen and Peter in 1185. Destroyed in the 13th century, it was reconstructed in the 1350s. Plundered in the 18th and 19th centuries, it was completely destroyed by an earthquake in 1913, leaving only the apse and fragments of frescoes. Reconstruction began in 1977–1985, led by Teofil Teofilov, based on architectural remains and examples from better-preserved Bulgarian churches. Two layers of frescoes, dating to the church's construction and the 14th century, have been preserved.
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.