Hagia Sofia

A Greek Orthodox church built in 537, Hagia Sofia became an imperial mosque in 1453, and then was opened as a museum in 1935. It's been undergoing restoration of its dome for 17 (!) years, so some of these photos are from the 1990 trip, since otherwise you would be unable to see much for the scaffolding. First, another one of those unnaturally perfect exterior photos that must have been from a slide I bought:

This is rather more what it looked like when I was there!

Outside were carvings of the Lambs of the Apostles, dating from when it was a church.

Fountain outside for performing ablutions prior to prayer:

Notice the Virgin and Child in the dome above the windows:

I love the old-style chandeliers in mosques:

The domes aren't too shabby, either:

Some of the features of the main floor of the building:

There's a beautiful upper gallery in Hagia Sofia called the Loge of the Empress, where the Empress and court ladies could watch what was going on down below:

 Mosaic of Christ, probably 1261, flanked by Mary and John the Baptist:

Spiderweb detail in the corner of one the arches:

Mosaic of Christ flanked by Emperor Constantine and Empress Zoe: