Meteora rocks are composed of a mixture of sandstone and conglomerate. The conglomerate was formed of deposits of stone, sand, and mud from streams flowing into a delta at the edge of a lake, over millions of years. About 60 million years ago during the Paleogene period, a series of earth movements caused the seabed to withdraw, creating a high plateau and causing many vertical fault lines in the thick layer of sandstone. The huge rock pillars were then continuously hit by strong winds and waves, which, in combination with extreme weather conditions, affected their shape.
The earliest inhabitants moved to the area 50.000 years ago, when the Earth was still experiencing an ice age. They established settlers within caverns which worked as a barrier against the cold winds. Many Paleolithic and Neolithic artifacts of human occupation have been found within the caverns. The first people documented to inhabit Meteora after the Neolithic Era was an ascetic group of hermit monks who, in the ninth century AD, moved up to the ancient pinnacles. They lived in hollows and fissures in the rock towers and this great height, combined with the sheerness of the cliff walls, kept away all but the most determined visitors.
As early as the eleventh century, monks occupied the caverns of Meteora. However, monasteries were not built until the fourteenth century, when the monks sought somewhere to hide in the face of an increasing number of Turkish attacks on Greece. At this time, access to the top was via removable ladders or windlass.
Between the 15th and 17th centuries, Meteora was at its prime with the arrival of many monks from other monasteries or people who wanted to lead an ascetic life in this divine environment. However, the prosperity of Meteora during that time started to fade away after the 17th century, mainly due to the raids of thieves and conquerors. These caused many monasteries to be abandoned or destructed.
Nowadays, of the 24 monasteries, only 6 are still functioning, with a handful of monks each. Getting up there is a lot simpler due to steps being carved into the rock during the 1920s.