Van Gogh’s visit to the Marcasse site is documented through a letter he wrote to his brother Théo in April 1879.
"Not long ago, I made a very interesting excursion; in fact, I spent 6 hours in a mine. And in one of the oldest and most dangerous mines in the area, called Marcasse […]. We went down together, this time 700 meters deep, and we were in the most hidden corners of this underground world. […] when looking up, you can barely see the daylight, about the size of a star in the sky."