The Stockholm Tunnelbana has three lines encompassing 110km of track and 100 stations of which 64km and 55 stations are underground. Several of the deep underground stations are cut into solid rock which were left with cave-like ceilings.

The builders carved fascinating artistic objects out of the rock. One like the base of a gigantic Greek column (Station Radhuset) resembles the excavated remains of some lost city of Atlantis encased in an ancient lava flow. The Station Kungstradgarden has torsos and lion heads emerging from the rock. Modern murals and statues are liberally used in many other stations.