This fort is located along the Amnya River in the western Siberia.
It was built 8.000 years ago and inhabited during the Mesolithic or Middle Stone age.
It is unknown what triggered the need for these fortified structures and who ordered the construction.
Remains include roughly 20 pit-house depressions. Each pit house was protected by earthen walls and wooden palisades.
[Source: www.livescience.com]
