The Oulu Cathedral is an Evangelical Lutheran cathedral and the seat of the Diocese of Oulu. The church was built in 1777 as a tribute to the King of Sweden Gustav III of Sweden and named after his wife as Sofia Magdalena's church.
The wooden structures burned in the large fire of the city of Oulu in 1822. The church was built again on top of the old stonewalls with famous architect Carl Ludvig Engel as the designer. The restoration works were completed in 1832, but the belfry was not erected until 1845.
Reference: Wikipedia
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.