The Historic Centre (Chorá) with the Monastery of Saint-John the Theologian and the Cave of the Apocalypse on the Island of Pátmos

This site has one of the longest names of the World Heritage list and it was where St. John wrote his Gospel and the Apocalypse 

Monastery of St John the Theologian

This postcard was sent by Elena

The Monastery of St. John the Divine (Agios Ioannis o Theologos), also known as the Monastery of St. John the Theologian, is a fortified Orthodox monastery on the island of Patmos in Greece.

In 1088, the Byzantine Emperor Alexios Komnenos gave the island of Patmos to the soldier-priest Ionnis Khristodhoulos "the Blessed." The greater part of the monastery was completed by Khristodhoulos in just three years. Its heavily fortified exterior was necessitated by the threats of piracy and Seljuk Turks. - in: http://www.sacred-destinations.com/greece/patmos-monastery-of-st-john