Roman Istanbul

Istanbul is focused very much on the Ottoman & Byzantine empires while glossing over the Roman history of the city (The Hippodrome with its ancient Egyptian obelisk isn't even marked on the local tourist map). I tend to think of Istanbul as a Roman city and glaze over the separation between the Roman Empire and the Byzantine period. This can make it difficult to see the parts of the Roman city.

The original Justinian palace is now partially buried under the Blue Mosque. However, part of the old palace has been found and the mosaics have been restored and remain at the original site in the Grand Palace Mozaic Museum.

The actual restoration of the mosaics was partially completed in the Haiga Irene which is itself linked to a Roman history. 

http://en.m.wikipedia.org/wiki/Hagia_Irene

Unfortunately, the stage is directly under the dome and most of the ceiling is covered by a net so I couldn't get a great dome shot. But as you can see from this photo it is very simple. 

And of course, the cistern, famous because they stole building materials from the surrounding area.