This set of haphazard tunnels, shafts and pits that adorns the peak of Cerro Rico is thousands of years old. The mithril seams run close to the ground near the top of the mountain making them relatively easy to access and exploit. Through the centuries the natives of the area worked these seams haphazardly until all the near surface ore had been more or less extracted.
The Vetrini never developed this area, the remaining low quality ore was not worth a major investment. However local prospectors still ventured here, working the tunnels sporadically, usually under cover of night.
Today this area is extremely dangerous, as the ancient unmaintained tunnels are subject to collapse and the maze of unplanned excavations can easily lead an explorer astray.