Spiennes is a Walloon village in the municipality of Mons, Belgium.
It is well known for its neolithic flint mines, which are on the list of UNESCO World Heritage Sites. The entry on the list describes them as "the largest and earliest concentration of ancient mines in Europe" and cites the level of human technological development they demonstrate as justification for their inclusion.
The mines cover some 100 hectares of downland near Mons in Belgium and are interesting for showing the transition between opencast and underground mining for the flint nodules. The nodules were extracted using deer antler picks. The stones were then knapped into rough-out shapes of axes, and finally polished to achieve the final state.
The rough-outs were traded over a wide area, and were often polished at their destination. Polishing strengthens the final product, making the axe-head last longer. The axes were used initially for forest clearance during the early Neolithic period, and for shaping wood for structural applications, such as timber for huts and canoes.
The site is comparable with Grimes Graves and Cissbury in Britain, which were also sources of flint. Other hard rocks were used for making polished stone axes however. There are many locations in Britain where fine-grained igneous or metamorphic rocks were collected from screes or mined opencast, then roughed out locally before trading on to other parts of the country. Examples include the Langdale axe industry, Penmaenmawr and Tievebulliagh.