Topic summary
Underground mine
Extracted from the Wikipedia article Mining.
Records
The largest underground mine is Kiirunavaara Mine in Kiruna, Sweden. With 450 kilometres (280 miles) of roads, 40 million tonnes of annually produced ore, and a depth of 1,270 metres (4,170 ft), it is also one of the most modern underground mines. The deepest borehole in the world is Kola Superdeep Borehole at 12,262 metres (40,230 ft), but this is connected to scientific drilling, not mining.