These are the remains of the largest structure erected by Hadrian (2nd century CE). Not just a library, it also held music and lecture rooms. It was laid out as a typical Roman forum, with a pool in the center of a courtyard bordered by 100 columns. The library's west wall, by the site entrance, has been restored. Beyond are only traces of the library, as well as two churches, built in the 7th and 12th centuries.
