For me, it really comes down to two places:
The deësis of Hagia Sophia
Despite being very non religious, I've been interested in religious art since I was a kid - my apartment is covered in sacred hearts and the virgin mary and my grandmother was convinced that I was going to become a nun. Whoops. Hell no! Anyway, Byzantine and Gothic art and architecture became my main obsessions and those are two of the most amazing examples of them. And Hagia Sophia is even more interesting because it was a Byzantium basilica that became a mosque and both of that is still there now.
Is this morbid? Anyway, share!