10 Euros - Philippe Neolithic Flint Mines Spiennes

The Neolithic flint mines at Spiennes, near Mons in Hainaut, represent the largest and earliest known concentration of prehistoric mining in Europe, active from roughly 4000 to 2000 BCE. Miners sank shafts up to fifteen meters into the chalk bedrock using antler picks, extracting high-quality flint that was traded across considerable distances. The site was inscribed on the UNESCO World Heritage List in 2000.

Belgium has issued commemorative tens in this series under the "Philippe" designation since his accession in 2013, with each coin anchored to a site of recognized cultural or scientific significance. Spiennes itself was first identified by geologists in 1867.