Kobuyamadani Settlement Site
The Kobuyamadani valley is located about 200 meters from the entrance to the Ryugenji mining tunnel, one of the central sights at Iwami Ginzan. When the silver mine flourished in the late sixteenth and early seventeenth centuries, a large mining settlement was built across the entire hillside. Houses and facilities for processing silver ore were constructed on flattened and terraced ground, at a convenient distance from the many mining tunnels dug into the rock. The Kobuyamadani settlement proved enduring: it was expanded gradually over the centuries and remained populated until the Meiji era (1868–1912). This was partially thanks to its relatively convenient location near the foot of Mt. Sennoyama, around which the silver mine was located. The low-lying setting, however, was also a curse: Kobuyamadani was often hit by floods, some of which caused severe damage.
In the upper part of the valley is the Shinyokoai mining tunnel, which was developed in the middle of the Edo period (1603–1867) and is a testament to the ingenuity of Kobuyamadani’s miners. To reach the vertical silver veins, the tunnel was dug into the mountainside horizontally and at a slight upward angle so that groundwater released by mining would flow out. Traditional mining tunnels were dug at a steep downward angle parallel to one or several silver veins, but they would sooner or later fill up with water. In addition to developing this innovative type of tunnel, the Kobuyamadani miners took up copper mining when the silver deposits in the area were depleted. These efforts were continued in the Meiji era, when the Fujita-gumi corporation acquired rights to Iwami Ginzan and built modern ore dressing and refining facilities in the valley. Those functions were moved to the nearby Kojidani area at the turn of the twentieth century, and Kobuyamadani fell silent after some 350 years of mining.