As I pointed out in the other post for the Hagia Sophia, there were many Christian Icons represented, as well as Islamic Calligraphy and symbols. In this photo you can actually see both--the small plates with the Islamic calligraphy and the picture of Mary at the top.
History never fascinated me as a child, and even now I am not extremely interested. However, when you visit places like this, it makes you interested. History becomes real and not just something you read in a book. I hope that one day when I have kids I'll be able to share with them things like this.