This kind of places can be found a lot in the Iwami Ginzan World Heritage area. Space to produce silver was created right in front of the shaft. It can be clearly seen that the walls aren't natural.
The ore was brought out of the shaft and crushed to small pieces. The silver is then produced through cupellation. Thousands of houses have been standing along the slopes of several valeys up to the top of the mountain where silver have been living and produced silver.
Minig was activ in the area from 1523 to 1926.