The Monastery of St. John has two libraries. One containing 'modern' books, newsletters and magazines is located up on the second floor. It is pictured here (1994 photo).
The other library, containing the rare manuscripts is located in the basement. The monastery has an extensive library of manuscripts and a large number of historically significant icons and other pieces of sacred art (such as vestments, crosses, chalices, patens, and pyxes). The library also holds many other biblical and patristic manuscripts, together with many manuscripts of Byzantine emperors, princes and patriarchs, including the act of donation by which emperor Alexios Comnenos ceded the island to Christodoulos.
See a picture of the librarian of the archival library.