Grove De Keel

If you could have looked up from here before the construction of the Albert canal between 1932 and 1936, you would have seen the underside of a couple of farmhouses at a crossroads of field paths.
From those farms, which formed the hamlet of de Keel, various wells were dug down to the marl. Through these shafts, marl has been mined since the mid-seventeenth century.
The thousands of cubic meters of marl blocks were hoisted up through the shafts to be used as building material. It was only after the canal was constructed that the current access tunnel was made to facilitate the transport of blocks and marl powder for the lime industry.
From 1940 to around 1970, the quarry was simultaneously used for the cultivation of cave mushrooms and lime extraction. Ultimately, the marl extraction has resulted in approximately seven kilometers of underground tunnels at four different levels.

Tourist Board South Limburg (Visit Zuid-Limburg)