Whether or not this is the largest art gallery in the world, spread out over the 110 kilometres of the underground network of Sweden's capital, it has to be the longest. And the admission fee is simply a single train ticket. That ticket to ride is a ticket to view, too, and you can travel the network and explore the art on display, or simply take in the view while en route to some of Stockholm's sights above ground.
On display in 90 of the 100 stops that make up the network is a selection of art particularly impressive not just due to its size and variety, but also because of the way that it interacts with and adapts to the different station environments. From the giant tulips on the platform at Hogdalen, to the installation of 'archaeological excavation' at Kungstradgarden, with remains of the old Makalos Palace and opera house, there are all types of art on display including sculptures, mosaics, murals, art installations, inscriptions and reliefs that are the works of hundreds of artists dating from the Fifties until today.
The first Stockholm subway station, built in the Fifties, where the idea of making art accessible to all audiences first took shape, was T-Centralen, and the walls here are still decorated with tiles and reliefs. But the project was extended to comprise many remarkable examples, among which Solna Centrum station is particularly impressive, with its great cavernous ceiling in bright red that seems to hang heavy over the platform. Juxtaposed with this, the walls of the station represent a spruce forest a kilometre in length.
The works of hundreds of artists are displayed throughout the Stockholm underground for the delight and enjoyment of all travellers. Of course the system is so big that it's pretty much impossible to see them all, so it's best to join one of the guided tours that are available. The modest price of a single metro ticket includes the chance to visit four or five stations accompanied by an expert. If time is short, your best deal is to buy a ticket at T-Centralen station and take the blue line to admire the displays at the stations of Fridhemsplan and Radhuset, then continue back along the same line to visit the works on view at Kungstradgarden.