7. Meteora, Greece
The Meteora is one of the biggest and most important building structures of Orthodox monasteries, located in Greece, second only to Mt. Athos. Its six monasteries were constructed in natural sandstone with support pillars, at the northern area of the Plain of Thessaly close to the Pineios River and Pindus Hills, in the middle of Greece. The closest city is Kalambaka. Metéora is protected by UNESCO World Heritage List.