Yesterday I got a postcard from Belgium.
It shows one of the Neolithic Flint Mines at Spiennes. The extraction of flint near modern day Spiennes started 6000 years ago and was continued until approximately 750 BCE. They form the largest and earliest concentration of ancient mines in Europe. The Neolithic Flint Mines at Spiennes are since 2000 on the UNESCO World Heritage List.
Butterfly (from set of two) (issued 25-06-2012)
Thank You very much Claas and Christine!