"The Jerusalem of the Aegean" is one way of describing Patmos or Patnos, as it was referred to in one 5th century inscription. It was here that St.John the Theologian was exiled between 95 and 97 A.D. and was inspired to write the Book of Revelation of Apocalypse.

Later the emperor Alexios Komnimos ordered the monk Christodoulos Letrinos to found a monastery in honour of the Apostle. Thus the holy monastery of Patmos was built, the most important landmark on the island.

Patmos, situated near the Turkish coast, is a mountainous island with rocky soil and an abundance of small caves. In one of these caves St John wrote the Apocalypse.

The construction of the monastery began in the 11th century. It is circumscribed by massive grey stone walls with battlements that protected the main church and another five chapels. Its extraordinary treasury contains Byzantine and post-Byzantine icons, sacred vessels, 9th century embroideries and other priceless objects, while its library houses parchment documents, patriarchal seals, illuminated manuscripts and rare old books. In the chapel dedicated to Our Lady frescoes can be seen which date to
1210-1220.