History
In 1871, Mercier decided to build an authentic underground town and, never a man to do anything by half, instructed his architect to count in kilometres, not metres.
Six years later, the champagne production facility boasted 47 tunnels, covering 18 kilometres, a direct rail connection to the Paris-Strasbourg rail network and later became a popular public attraction when Mercier began running guided tours for the public - something that cont...