It wasn’t until I explored Stockholm’s subway system that I realised a train network wasn’t only a means of transport; it could also be a repository of art and artistic experiments. Stockholm’s first underground train line opened in 1950, running between Slussen and Hokarangen stations. The idea of “art in the metro” was inspired later in the decade by a new political ideology known as Folkhemmet, or The People’s Home, led by the Swedish Social Democratic party. “People felt art needed to be more accessible to people on the streets instead of being the preserve of the rich and the famous,” says Anders Nilsson, a fellow art enthusiast I meet while exploring Moderna Museet, the state museum for modern and contemporary art. "As Stockholm expanded and many people moved to the suburbs, the subway system worked well to connect the city and ensure that art was accessible to all." Today, the T-Bana, or tunnelbana, which in Swedish means tunnel railway, has 100 stations, 47 underground and 53 above ground. It is a veritable, open-to-all 110-kilometre art gallery that lets you get up close with stupendous murals, intricate paintings and playful art installations. In a city known for its for dull, grey winters, the democratisation of art has livened up people’s daily commute. For the price of a train ticket, one can explore the 90 stations decorated with mosaics, paintings, sculptures, installations, reliefs and engravings by more than 150 artists. It seems like a wonderful, inexpensive way to look at the evolution of art – from the 1950s to modern experiments – and the work of many artists who have since become well-known figures in Sweden. The ideal place to kick off a T-bana tour is T-Centralen, the city's main train station where the three lines – red, blue and green – of the Stockholm Metro intersect. T-Centralen, the first subway station to be built in Stockholm, was where the idea of adding artwork to stations came alive. Many of the original sculptures and paintings date back to the late 1950s, but the most memorable – including one with blue lines and floral motifs intended to create calm and quietude – were created by sculptor and painter Per Olof Ultvedt. He also gave pride of place to the workers who built T-Centralen by painting their silhouettes on the walls and ceilings. The 25.5km-long blue line stretches between Kungstradgarden and Akalla/Hjulsta stations. After boarding a train to Viksjo, I hop off at Hallonbergen, the seventh stop from T-Centralen, and find that artists Elis Eriksson and Gosta Wallmark have recreated the imaginative world of children in a work sure to bring a smile to the fact of even the most jaded commuter. The little doodles and scrawls, etched in black on white, include humans, horses and fantastical little beasts. Eriksson and Wallmark are said to have used their own childhood drawings and those made by their children to decorate Hallonbergen, a word that translates to Raspberry Mountains, which sounds like something straight out of a children's fairy tale. Next stop is Solna Centrum, which offers one of the most famous images of Stockholm’s Metro. The cave-like station has a sky painted blood red and a vivid green, with a 1,000-metre-long spruce forest that runs below. Anders Aberg and Karl-Olav Bjork in 1975 created this artwork to make a stand against the destruction of the environment, forests and nature taking place during the peak of Sweden’s industrial era. Kungstradgarden is the terminus of the blue line, with artwork that draw inspirations from the King’s Garden, one of Stockholm’s oldest public parks. The vibrant and abstract harlequin ceiling design that seems to consume the cave was painted by Ulrik Samuelson in 1977. Marie Andersson, a certified subway art guide, believes the underground station tells the story of the site above ground. “The colour scheme of the station – red, white and green – references the old French official garden,” she says. The statues around the station are copies of exterior art at Makalos Palace, which was built in Kungstradgarden in 1635 and burned down in 1825, she adds. At Ostermalmstorg, a station designed in the 1960s to serve as a shelter in case of nuclear attack, painter and sculptor Siri Derkert chose to create a political statement by using images that focus on women’s rights and world peace. Derkert, a pioneer of Swedish 20th-century art, studied at the Royal Swedish Academy of Arts, and moved to Paris in 1913. She returned to Sweden with a strong passion for women’s rights and chose to represent historical female figures with a special sand-blasting technique on the station’s walls. The women include Hypatia, one of the earliest “mothers of mathematics”; Sappho, the fifth-century lyrical poet from Lesbos; French writer Simone de Beauvoir; and British author Virginia Woolf. The word “peace” in different languages takes pride of place across the walls alongside etchings of people who worked for the environment and on women’s rights. Hotorget, on the Green Line, is often called the “bathroom” station on account of the light teal tilework and vintage signposts. When I look up, I see the drama and movement artist Gun Gordillo created by placing 103 strips of winding neon lights along the ceilings in 1998. Christian Partos, who worked on the Teleportations artwork at Hasselby Strand station in 2000, applauds the idea to use artistic decoration to make the stations more distinct. “Train stations mostly lack any architectural characteristics, and this art defines the space,” he says. For his contribution to the T-bana, he focused on emphasising the elevator as an element of form by giving it a different surface – a yellow chromatic plate – and a tile pattern that is almost humorous. “The elevator has become the one part of the station that everything emanates from, in spite of not existing in the original plan. The spirals out of the wall and the ring-patterned holes in the floor, generate from the elevator’s field of force,” he says. Moving on to Morby Centrum, I find that artists Gosta Wessel and Karin Ek succeeded in their mission to showcase the change that a journey brings. The colourful tilework creates an optical illusion, with the walls changing colour depending on where I stand. And then it’s time for the stunning showpiece at Stadion station, located near Ostermalms IP, a stadium that was the site for the 1912 Olympics and now hosts sports events and concerts. The artwork at one of Stockholm’s first cave stations, by Ake Pallarp and Enno Hallek, serves as a reminder of Stadion’s significance in sports history. It’s a wonderful coincidence that a bright and beautiful rainbow stands out against the station's bright blue walls. According to Visit Stockholm, the station created controversy when it was built in 1973, with fears that people would associate a cave station with the netherworld. But the bright blue and the rainbow “serves as a reminder that there is a sky not far above”. The beauty of Stockholm’s subway system leads me to pause time and again – the very opposite of what train stations are typically programmed to do. Commuter stations across the world are usually populated by a horde of workers all walking quietly and swiftly, phone in hand, and no time to waste. But the T-bana, despite the escalators, stairways and bottlenecks, differs by offering another journey alongside – a chance to time-travel through Swedish art and culture.