When Hirschau, Bavaria starting mining kaolinite a century ago, it faced a problem — one of the byproducts of kaolinite is quartz sand, which began piling up in enormous quantities. Fortunately sand itself has multiple uses — in the early 1950s an enterprising skier tried slaloming down the mountain, and soon the dune had its own ski club.

Today the 35-million-tonne “Monte Kaolino” even hosts the Sandboarding World Championships. And, unlike other ski resorts, it’s open in summer.