The Haghia Sophia (Aya Sofya) is a church dating back to 1228-1263. It houses some very fine frescoes. It is a major sight of the city.
This is a complicated fresco, one of the evangelists to the left, Christ carrying a cross, but doing what? I think he may be visiting the people who were thrown in hell, and was later informed On the left is St. John Theologos. The scene on the right is called the Descent of Christ into Limbo the byzantine style representation of the Resurection. It's a new edit of a slide I scanned again and edited in 2018.