Kongsberg Silver Mines
The silver mines of Kongsberg, in Buskerud county in Norway, constitute the largest mining field in Norway, with over 80 different mines. It was the largest pre-industrial working place in Norway, with over 4,000 workers at its peak in the 1770s and supplied over 10% of the gross national product of the Danish–Norwegian union during its 335-year-long history: over 450,000 man-years were expended in the production.
Holdong mine
The Holdong mine is one of the largest gold mines in North Korea and in the world. The mine is located in the south of the country in North Hwanghae Province. The mine has estimated reserves of 63.2 million oz of gold and 149.8 million oz of silver. The mine also has reserves amounting to 520 million tonnes of ore grading 0.35% copper metal and 266 million tonnes of ore grading 26% iron metal.