Patmos the island of Apocalypse
The 14th year of the kingship of the Roman Emperor Domitianos, circa 94 or 95 AC, John the Evangelist was exiled from Efesos to Patmos. There, according to tradition, John communicated with God whilst in a cave, which exists until today and is named "The Holy Cave of Revelation". It was there and then that God revealed the book to John and the latter recorded it with the help of his student Prohoros.
The tradition also says that in the cave, a rock was torn in two and from there, from three smaller cracks which stand as a symbol for the Holy Trinity, one could hear God's voice as he was dictating the text of the Apocalypse to John. The cave has been transformed to a worshiping place from the founder of the Patmos Monastery, Christodulos and today a church is included on the Southern side.