The Swedes have no need to chase rainbows when there is already one at Stadion subway station in Stockholm, Sweden.

Located along the Red line, the station is full of sculptures and signs designed in the bright rainbow colours of the Olympic rings, said the BBC. They were designed by artists Enno Hallek and Ake Pallarp in 1973 to commemorate the 1912 Olympics, which took place at Stockholm Stadion (or Stadium), after which the station was named.

At 110km long, the Stockholm subway system is said to be the world's longest art exhibit, according to the Visit Stockholm website. More than 90 of its 100 stations have been decorated with sculptures, mosaics, paintings, installations, engravings and reliefs by over 150 artists.

Stockholm Metro carries more than 1.2 million people every day, according to MTR Nordic, which owns the firm operating the metro.

The artists selected to work on the stations were passionate over social issues such as women's rights, rural depopulation and deforestation, said The Guardian.

Travel site Expedia has a microsite titled Underground Art (www.expedia.se/vc/c/konstsparet/en), which gives a virtual tour of some of the stations.