The Meteora , (lit. "middle of the sky", "suspended in the air" or "in the heavens above" - etymologically related to "Meteorite") is one of the largest and most important complexes of Eastern Orthodox monasteries in Greece, second only to Mount Athos. The six monasteries are built on natural sandstone rock pillars, at the northwestern edge of the Plain of Thessaly near the Pineios river and Pindus Mountains, in central Greece. The nearest town is Kalambaka. The Metéora is included on the UNESCO World Heritage List under criteria I, II, IV, V and VII.