GERMANY: 'Externsteine' rock pillars - Teutoburg Forest

'Externsteine' is a distinctive rock formation located in the Teutoburg Forest of northwestern Germany, not far from the city of Detmold. It is a natural outcropping of five sandstone pillars, the tallest of which is 37.5m high. They form a wall of several hundred metres in length, in a region that is otherwise largely devoid of rocks. The geological formation consists of a hard, erosion-resistant sandstone, laid down during the early Cretaceous era about 120 million years ago, near the edge of a large shallow sea that covered large parts of Northern Europe at the time. The pillars have been modified and decorated by humans over the centuries in a variety of fascinating and mysterious ways: holes were drilled for no apparent reason; stairs lead to dead ends; platforms serve no clear purpose. An undeniably mysterious and magical place, Externsteine is thought to have been a pagan cultic center until Charlemagne abolished Saxon paganism in 782 AD. It was then used by Christian hermits throughout the Middle Ages. At the top of the tallest stone is a chamber, now open. Formerly used for sacrifices, little decoration remains apart from one wall with a circular hole cut into it. Studies have shown that this is some form of calendar. On the exact day each year when summer turns to winter, the sun shines exactly onto this hole. September 19, 2010