Kongsberg Silver Mines are among Norway's great industrial-history sights. The mines operated from 1623 to 1958, with hundreds of shafts and a vast tunnel system dug into the hills west of town.
The public tour is the draw. A small train carries visitors into the mountain through the Christian VII Adit, making the darkness, distance, and hard labour of the old works feel immediate. Bring warm clothing even in summer; underground Kongsberg has its own climate.