An underground limestone quarry. Parts of it are no longer in use and developed a beautiful natural area with unique flora and fauna.
Wikipedia (Dutch) http://nl.wikipedia.org/wiki/Groeve_'t_Rooth
Official website http://www.limburgs-landschap.nl/gebieden/groeve-t-rooth
Address 6268, Netherlands
Coordinates 50°50'27.859" N 5°47'8.97" E
