Dalum church originally consisted of Romanesque style nave, choir and apsis, built in the 1100s. The tower was added later during the same century. The sacristy was built in 1300s and church got its Gothic details. The tower destroyed in 1500s and the new one was erected in 1600s during the restoration. The bell tower dates from 1693. The current altar dates from 1693.
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.