OSM tag name=Mertainen matches Mertainen in these Wikidata fields:
Former mines in Sweden | gnis:feature_type=Mine, landuse=quarry, man_made=mine, industrial=mine, man_made=mineshaft |
Iron mines in Sweden | gnis:feature_type=Mine, landuse=quarry, man_made=mine, industrial=mine, man_made=mineshaft |
Surface mines in Sweden | gnis:feature_type=Mine, landuse=quarry, man_made=mine, industrial=mine, man_made=mineshaft |