At the heart of Hainaut province in Belgium, literally a stone's throw from the city of Mons, sit Spiennes and Nouvelles, two villages which conceal archaeological wonders. Here 6,000 years ago Neolithic men dug thousands of underground mines to extract flint for the production of polished axes and blades. The sheer size of the site, combined with the duration of its exploitation and its archaeological potential for future research, was all acknowledged by UNESCO in December 2000…