Spectacularly perched atop rocky pinnacles in Thessaly, the Meteora monasteries are among the most striking sights in Greece. The name Meteora (Μετεωρα) is Greek for "suspended in the air," which perfectly describes these six remarkable Greek Orthodox monasteries. The sandstone peaks were first inhabited by Byzantine hermits in the 11th century, who clambered up the rocks to be alone with God. The present monasteries were built in the 14th and 15th centuries during a time of instability and revival of the hermit ideal; the first was Great Meteoron (c.1340) and there were 24 monasteries by 1500. They flourished until the 17th century but only six survive today; four of these still host monastic communities.
More pictures from Meteora could be found here: http://www.mikereyfman.com/photo/gallery.php?Gallery=Meteora-Monasteries-Greece