A female member of Romania's military adjusts her hat before taking part in the national day military parade in Bucharest, Romania, Friday, December 1, 2017. Thousands of Romanian troops staged a military parade to celebrate Romania's national day, but key politicians didn't attend, signaling tensions between the president and the ruling left-wing coalition over plans to revamp the justice system. (Photo by Vadim Ghirda/AP Photo)

This fascinating photo series looks at the bleak isolation of Chernobyl as never before. Employing infrared filters, photographer Vladimir Mitgutin is able to bring out details of decay – an abandoned bus, a radar system, an amusement park, a doll, a sports hall, a piano – frozen in time. Here: Simon – a friendly fox, who often approaches tourists in the exclusion zone, asking for food. (Photo by Vladimir Mitgutin/Caters News Agency)

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)

The illustrations created by Joao Carvalho are not just simple 3D drawings. By making it look as if various characters were drawn on regular note book paper, Joao fools our minds into thinking that the flat objects we see on the picture are actually 3-dimentional. To create these pieces of art, Joao first draws the lines of the “notebook” paper already bent, as if they stretch over the object that is about to be drawn. Then he applies shading and his masterpiece is all done! By looking at his pictures it is almost impossible to view them not as simple 2D drawings, but as real 3D objects. (Photo by Joao Desenhos)

Meet Booboo, the 2-year-old guinea pig. Her hobbies included eating chicory and posing for pictures. Described optimistically as ‘spirited’ by owner Megan, she can generally be found knocking about with her guinea pig crew, Titi and Teddy. But don’t worry, these gangsta guineas are lovers not fighters (didn’t the chicory give you a clue?). In fact, they’re pretty cerebral, often to be found quietly reading a book, or staring contemplatively into the distance next to a sprig of lavender, that kind of thing.

Full-time feline photographer Andrew Marttila from Washington, D.C., captured blissful expressions of various cats on catnip, which he used to compile a book, “Cats on Catnip”. The photographer dedicated his time to capturing the euphoric expressions of kitties high on catnip – and the results are absolutely hilarious. (Photo by Andrew Marttila/Caters News Agency)

Roland Miller is on a mission to document the deserted sites of America’s space race. He has photographed launch pads, bunkhouses and research facilities across the country, some of which no longer exist or are closed to the public on secure military bases. His book, “Abandoned in Place”, is published by the University of New Mexico Press in March. Here: Launch Pad and Gantry with Hermes A-1 Rocket – V2 Launch Complex 33, White Sands missile range, New Mexico in 2006. (Photo by Roland Miller)