This was my favorite afternoon in Istanbul. Quiet and cold, and slow. Sultan Ahmed, also called the Blue Mosque, is a functioning mosque. As with a cathedral, faith comes first, and travelers must wait until services and prayers are finished. I would wait all day in that lovely courtyard, listening to the echoing sounds of the muezzin from the Blue Mosque and the Firuz Aga Mosque take turns calling the faithful to prayer.
Here are two videos of the calls to prayer that echo back and forth from the Blue Mosque and Firuz Aga Mosque. I was caught a little off guard the first time I heard it, and felt very swept up and emotional. The first (bad) video is mine, the second (much better) video was found on Youtube.