Meteora, Greece is one of the most fascinating and spectacular places I have ever visited. It's a four hour drive north of Athens and has an incredibly rich history. Meteora translates as "suspended in the air".
Caves in Meteora were inhabited continuously between 50,000 and 5,000 years ago and the monks settled here in the 11th century. The monasteries were built in the 14th - 16th centuries and the monks found the inaccessible rock pillars an ideal refuge from the expanding Turkish occupation, and the area was also attacked by the Nazis during WWII.
Today all of the monasteries pictured above are still functioning monasteries. I recommend ditching your car and exploring the region by foot.