Ephesus is an ancient Greek/Roman city, home to the well-preserved facade of the Great Library of Celsus, which is believed to be the third-largest library in the Roman world behind only the ones in Alexandria and Pergamum.You will also find the Ancient Theatre of Ephesus, another impressive architecture that shows just how adept the Romans were at constructing such a massive structure. It is said that the theatre can hold more than 20,000 spectators which is mindblowing considering it was built more than 2,000 years ago.