The Monastery of Saint John the Theologian (also called Monastery of Saint John the Divine) is a Greek Orthodox monastery founded in 1088 in Chora on the island of Patmos. UNESCO has declared it a World Heritage site. It is built on a spot venerated by both Catholics and Eastern Orthodox as the cave where St. John of Patmos had visions. In 2012, 40 monks reside there.
In 1088, Byzantine Emperor Alexios I Komnenos gave the island of Patmos to the soldier-priest John Christodoulos. The greater part of the monastery was completed by Christodoulos three years later. He heavily fortified the exterior because of the threats of piracy and Seljuk Turks. 330 manuscripts are housed in the library (267 on parchment), 82 manuscript of the New Testament.