This metro station at Fridhemsplan shows how rough and cave-like some of the stations in Stockholm can appear.
But you can see the man-made elements at many stations. The Rådhuset station features concrete columns that fit with the aesthetic of the courthouse above the station.
Note the roughly carved, ochre-colored arc, juxtaposed with the perfectly smoothed concrete that supports the ceilings.
The Stadion Station in Stockholm is located at the city's former Olympic Stadium, built when the city hosted the games in 1922.
Equally as vibrant, the Alby metro station is completely covered in a grass-like green color. The designs are inspired by local petroglyphs, or ancient stone carvings.
The Solna metro station is painted bright red and black. The black gradually lightens into a pastel green, which eventually reveals itself as the backdrop for an evergreen forest.
This striking red emergency emergency exit passageway is built right into the Universitetet Metro station.
The Tensta metro station is decorated with birds that sit above a painting of a walrus in an arctic scene.
Swedish artist Ulrik Samuelson painted the murals that line the ceilings of the Kungsträdgården metro station in the 1970s. The station also holds relics and debris from buildings that were torn down during central Stockholm's reconstruction in the 1960s.
This blue mural showing vines and flowers is located in the T-Centralen station, arguably the city's most trafficked metro station with 330,000 passengers a day.
Source: SL