The Met?ora is one of the largest Eastern Orthodox monasteries in Greece. It comprises of six monasteries ? all built upon natural rock pillars. The Met?ora has been included in the UNESCO World Heritage list. These monasteries are created upon high cliffs and can be reached by stairways cut in these rock formations. According to the studies, these summits were shaped by earthquakes and weathering about 60 million years ago ? in the Paleogene Era.