Meteora, Greece

The Meteora  is one of the largest and most important complexes of Eastern Orthodox monasteries in Greece, second only to Mount Athos. The six monasteries are built on natural sandstone rock pillars, at the northwestern edge of the Plain of Thessaly near the Pineios river and Pindus Mountains, in central Greece. The nearest town is Kalambaka. They were the first people to inhabit Meteora. They lived in hollows and fissures in the rock towers, some of which reach 1800 ft above the plain. This great height, combined with the sheerness of the cliff walls, kept away all but the most determined visitors. Initially the hermits led a life of solitude, meeting only on Sundays and special days to worship and pray in a chapel built at the foot of a rock known as Dhoupiani.  Source