Travelling on a city's underground system is never expected to be an exciting experience - rather a convenient way of getting from A to B. But this could not be farther from the truth in the Swedish capital Stockholm, where artists have transformed the city's subway into a gigantic, kaleidoscopic art exhibition.
Around 90 of the city's 100 subway stations have been given a dazzling makeover by over 150 artists, who have been let loose over the last 55 years.
The results are spellbinding, transforming the subterranean transport system into a world of colour and visual stimulation, rather than somewhere to rest amongst the rats while waiting for your train to come.
The makeover has also helped to make the subway system - widely regarded as the most beautiful in Europe - into the world's longest art exhibition, measuring 110 kilometres (68.3 miles).
This series of breathtaking photographs captures the artistic beauty of the subway.