Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

Photographer Joana Choumali’s latest project explores body image and beauty by documenting the men building Abidjan’s clothing models. The “Awoulaba” mannequin is a customised model designed with the African ideal of beauty in mind, curvier than the stick-thin examples usually seen in the west. They first appeared in 2011, and have since become a familiar sight outside the numerous clothing shops dotted throughout Ivory Coast’s capital, Abidjan. Here: An apprentice lines up his work on a roadside. (Photo by Joana Choumali)

Wildlife photographer Danté Fenolio has headed into areas untouched by sunlight – deep seas, caves and underground – and found creatures that are exploding with colour. Here: The golden harlequin toad has vanished from the wild, and only a small number live on in captivity. A fungus caused them, and many other amphibians, to die out in their home in Central America. (Photo by Danté Fenolio/The Guardian/Johns Hopkins University Press)

Giffords Circus’s show is touring the UK. Established in 2000, Giffords Circus is a small circus company that delivers circus / theatre fusion to the villages and market towns of the south west. It combines dance, comedy, horses and live music in a two-hour show, located on village greens in a small white tent surrounded by handmade burgundy and gold showman’s wagons. Photographer Tom Pilston goes behind the scenes to meet the performers. Here: The incredible, gravity-defying Konjowoch Troupe. (Photo by Tom Pilston/The Guardian)

Chris Staring photographs a mysterious train graveyard in the heart of southern Bolivia, where the skeletons of British steam locomotives and rail cars rust away on the edge of the world’s largest salt flats. More than 100 rail cars and locomotives can be found in different states of decay in the train graveyard. (Photo by Chris Staring/Rex Features/Shutterstock)

Cars sit abandoned in a former shopping centre in the United Nations buffer zone in central Nicosia March 12, 2014. The cars were imported from Japan to be sold at a Toyota dealership. They were stored here during the 1974 conflict and have not been moved since. (Photo by Neil Hall/Reuters)

Netapp Endura team rider Slovenian Blaz Jarc (R) crashes into Katusha team rider Russian Viacheslav Kuznetsov (ground) during the 112th Paris Roubaix cycling race, in Roubaix, France, 13 April 2014. (Photo by Nicolas Bouvy/EPA)

Macro or Micro? Scientists’ pictures baffle our sense of scale. It began when Stephen Young, a geography professor at Salem State University in Massachusetts, tricked his biologist colleague Paul Kelly into thinking a satellite image was one of his electron microscope scans. Can you guess whether they are close-up or very far away? (Photo by Paul Kelly)