Kiirunavaara Mine, Kiruna, Lappland, Sweden

One of the largest underground mines in the world. The orebody is a slice of (apatite-bearing) magnetite 4 km long, 80 m wide stretching to an estimated depth of 2 km at an inclination of 60 degrees. Present main level is at a depth of 1045 meters.

The new main level at 1365 m is planned to open in 2012.

References:
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 960, 998.

Flink, G. (1924): Bidrag till Malmbergsgruvornas och Kiirunavaaras mineralogi.

http://www.mining-technology.com/projects/kiruna/