About four hours northwest of Athens, in central Greece, there’s an extraordinary rock formation known as the Meteora. It’s a series of enormous rock pillars that rise up from the edge of the plain to dominate the landscape.

But the geology of the Meteora is not its only unusual feature; perched atop the giant rock columns is a series of ancient Orthodox monasteries. And when you see them, the first question that comes to mind isn’t why, but how?