Located on the hill between Skala and Chora, the Holy Cave of the Apocalypse is a point of reference not only of Patmos, but of Christianity worldwide. This cave was the shelter of the beloved disciple of Jesus, John, in 95 AD, when the Emperor Domitianos exiled him to Patmos, punishing him for declaring the Word of God in Ephesus. As John testifies , he didn't reach Patmos as an exiled loser or as a political prisoner in difficult times, but as an exile "on a spiritual mission", continuing to disseminate the Word and the Essence of God.

In his exile and in this spiritual mission he is accompanied by his faithful disciple Prochoros. According to Christian tradition, during John's stay in the cave, the rock was torn, and through three smaller slots, symbolizing the Holy Trinity, the voice of God was heard, dictating John the Holy Book of Revelation. It is plausible that in this very same cave the fourth Gospel of John was also writen.

From the 17th century the temple of St. Anna was incorporated next to the holy cave, which was built by Osios Christodoulos as a tribute to: the mother of Virgin Mary, the mother of Osios himself, whose name was Anna, and the mother of the emperor Alexios Komninos. At the right of the church is the Holy Cave of the Apocalypse, within which lies the holy temple of St. John the Theologian. The cave is part of a complex of churches and other buildings (warehouses, cells, chapels) named "Revelation".

Today, the Holy Cave of the Apocalypse has been transformed into a place of worship, where the pilgrims can see the location where the Apocalypse was written, touch the triple fissure in the rock, enter the point at which the Evangelist rested, as well as touch the indentations in the rock that helped him to get up. Furthermore, there, one will also find the lectern of Prochoros.

The cave of the Apocalypse is a place of devoutness, where the pilgrims can be initiated in the beauty and awe through silence, feel, prayer and insight. They can also sense the feeling generated by the image of this magnificent Sanctuary Cave.

In 1999, the cave was declared a "World Heritage Monument" by UNESCO along with the Monastery of Saint John the Theologian.