Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: It tells of a city where empires, cultures and religions collided. A building that bears mosaics of Jesus and the Virgin Mary beside calligraphy reading "Allah" and "the Prophet Mohamed". There is no greater symbol of the clash of civilisations here than Hagia Sophia.

Pope Francis visit: Turkey's Christians face tense times