If you just glance at the picture, you might not notice it. But look carefully. You can see the facades of the ancient Soumela Monastery, founded in the fourth century CE.

The walls, punctuated by the windows of the monks' cells--though the monastery lost its last inhabitants in the 1920s--give a sense of the scale of the complex.

The monastery enjoyed the patronage of Byzantine emperors and even Ottoman Sultans, so revered was this spot, where a miraculous image of the Virgin Mary was said to have appeared in a cave in the cliffs behind.

This view gives you a sense of how inaccessible the location was. Even today, it's a long bus ride from the Black Sea city of Trabzon to get to this protected site in the mountains. The monastery seems to hang from the cliffs, as if part of the geology of the place.

If you look closely, though, you see that the buildings aren't attached to the cliffs, but are built along a ledge below them.

Dozens of monks once lived here. They had kitchens, numerous chapels, a dining room, and even a suite for the Byzantine emperor.

A great staircase brings you to the buildings, and then you find out that there's a large space behind them, also filled with structures: chapels, churches, and shrines.

In this area, to the left, the cave shrine is walled up to make a cave-church, the exterior walls of which are covered in fresco paintings. So, too, is the interior of the cave itself.

One of the frescoes on the exterior shows the creation of Eve from the rib of Adam.

Another shows the result of Adam and Eve's sin: the expulsion from the garden of Eden.

The natural stone walls of the cave-church are also covered in frescoes...

Such as these angels.

One of the largest images shows the Virgin Mary with the child Christ.

Theologically, the most important image in the cave-church is the fresco of Christ Pantocrator, meaning 'Creator of All'.