The Library of Celsus is an ancient Roman building in Ephesus Turkey. It was built in honour of the Roman Senator Tiberius Julius Celsus. The library was "one of the most impressive buildings in the Roman Empire" and built to store 12,000 scrolls and to serve as a mausoleum for Celsus, who is buried in a crypt beneath the library in a decorated marble sarcophagus. The Library of Celsus was the "third-largest library in the ancient world" behind both Alexandria and Pergamum.