Goseck circle

The Goseck circle is a Neolithic structure in Goseck in the Burgenlandkreis district in Saxony-Anhalt, Germany. It may be the oldest and best known of the Circular Enclosures associated with the Central European Neolithic. It also may be one of the oldest Solar observatories in the world.^[2][3] It consists of a set of concentric ditches 75 metres (246 feet) across and two palisade rings containing gates in places aligned with sunrise and sunset on the solstice days.

• http://en.wikipedia.org/wiki/Goseck circle