This is NOT contemporary art but the shift bosses’ change room (Steigerkaue) in the world heritage site of Rammelsberg mine. Instead of lockers the shift bosses used these baskets for storing their clothes and put them high up in the hall. A similar change room (Kaue) for miners I saw at the cocking plant Hansa in Dortmund.
There are several underground tours exploring the Rammelsberg Mine. I took the shortest one which goes through the Roeder Gallery. On this tour you follow the route of the water, channelled into the mine to set big water wheels in motion.