Share The quarries (pictured), which 'roofed the world' in the 19th century, have competition Bologna, Nice and the Ribeira Sacra wine district in Spain Backing the Welsh bid, Prime Minister Boris Johnson described the region as ‘an area of remarkable uniqueness and breath-taking beauty’. A decision from Unesco is due in the coming days. Unesco is said to have warned that Stonehenge could be the next British site to lose its coveted status if a £1.7bn road tunnel goes ahead as planned. Slate has been quarried in Wales for more than 1,800 years. Archaeologist Dr David Gwyn, who is part of the bid team, said: ‘The slate industry is an iconic feature of north Wales, and of the Welsh nation as a whole, and has been of overwhelming importance in shaping our social and economic landscape.’