Hagia Sophia is the most amazing monument of Istan...

Hagia Sophia is the most amazing monument of Istanbul. A must-see place for the first time visitors. Make sure to visit the upper gallery where Christian mosaics are and of-course the mausoleum section which has tombs of several Ottoman Sultans.

If you purchase the museum pass or attend to a guided tour you don't wait for the ticket line- which sometimes can last about 45 minutes. And finally, don't forget that Sophia is closed on Mondays.