Hagia Sophia, built in 537 AD. It is a marvelous p...

Hagia Sophia, built in 537 AD. It is a marvelous piece of history. Once you step in, it feels like you've gone back to the Byzantine period. You can do the line or pay a little extra and get a guide at the entrance. It will help you skip the long line and to understand the history of Hagia Sophia.