orecastDrive through the Ruhr today and you see residential streets, spoil-tip viewpoints and winding towers turned into museums. What you do not see: beneath all of it lies a second world. A network of shafts, galleries and mined-out chambers, dug by generations of miners, stacked in several levels, in places more than a thousand metres deep. Our new episode climbs down and shows where this world is documented to this day.
A century of coal
Coal turned villages into one of the largest industrial regions in the world within a few decades. Hundreds of collieries produced what blast furnaces, railways and power stations across Europe burned, and hundreds of thousands of miners went underground every day. At the end of 2018, Prosper-Haniel in Bottrop closed as Germany's last hard coal mine. Production is history; the hole in the ground is not. What was dug stays dug.
1,202 points on the map
That is what the map in this episode is about: 1,202 documented shafts, galleries and other mining features in the Ruhr area alone, drawn in orecast's caves and mining layer. The points come from open, documented sources, and our honesty line applies as always: the map shows what is recorded, not everything that lies below. In the Ruhr, old workings are so dense that voids keep turning up that were on no map at all, sometimes as a sudden sinkhole in someone's front garden.
A task with no end date
And this second world keeps working. Without the pumps that hold the mine water down forever, it would eventually rise back into the cellars; in the region they call these the eternity tasks. Mining is over, but it is not gone. If you want to understand why streets in the Ruhr subside and surveyors check the old-mining register before a house purchase, the answer lies a few hundred metres below the doormat.
Important: Old galleries and shafts are life-threatening. They can collapse, be flooded or hold deadly gases. Never enter them. The map is for looking and understanding, not for climbing in.