Clay Cross Tunnel goes under the town from Egstow to Clay Lane.
In 1830 George Stephenson started to build the railway line from Leeds to Derby. In the way stood the hill of Clay Cross. The only way for the line to continue was to construct a tunnel with a length of just over a mile straight through the hill.
Work started on the tunnel on 12 February 1837 Six shafts were sunk along the route to a depth of 150 feet 46m. At night a large fire was lit on each shaft to provide light and ventilation to hundreds of workers (navies) working below. The navies then tunneled 12 faces to construct the tunnel. The shafts are sill visible in Clay Cross and are still used for ventilation of the tunnel.
Once tunneling started it soon became obvious that the land contained wet coal. The seams of coal created many jobs in the local area and Clay Cross started to grow into the town we see today. Clay Cross tunnel was completed in 1839 at a cost of £140.000 sum £42.000 over the expected to be £98.000
Thank You Dave Harris. This an excellent video about Clay Cross Tunnel.