Spring 2012 - Istanbul
Where do I start? The Hagia Sophia was built in the 6th century by the Roman/Byzantine (depends on who you ask) Emperor Justinian. The Church was built very soon after riots had destroyed the previous church on the site. There are many things about the design of this church that made it groundbreaking for it's time, but perhaps the one that hits you the most upon entering (and is most clear from the photos) is the way the central dome seems to float without visible support.
The third photo is of the Blue Mosque (seen in my last post) from a window of the Hagia Sophia. The Hagia Sophia is actually cited for being a major influence on the design of the Blue Mosque, as well as many other mosques throughout the Ottoman Empire.
The whole thing is absolutely breathtaking - I would go so far as to say the most beautiful church I have ever been in, and I have been in many.