The Church of the Holy Saviour or Sveti Spas in the UNESCO World Heritage town of Nesebar, Bulgaria, is a 17th-century church building, 11.70 m long and 5.70 m wide, consisting of a single nave and apse.
Although small, it is notable for its early 17th century wall paintings representing scenes from the Life of Christ and the Holy Virgin, with a painting of the Virgin Platytera in the apse.
The tombstone of the Byzantine princess Mataissa Cantacuzina, formerly here, is now in the Nesebar Archaeological Museum. The church itself is de-consecrated and is also used as a 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.