Children look at Hares and Ducks ahead of the Turkey and dressed poultry auction at Chelford Market, northern England December 22, 2014. (Photo by Phil Noble/Reuters)

The fin of a tuna is seen on display in the outer part of the Tsukiji fish market, the Jogai Shijo, in Tokyo January 4, 2015. The famous Tsukiji wholesale fish and seafood market, is scheduled to leave its fabled 80-year-old halls to move into bigger, more modern facilities next year ahead of the 2020 Tokyo Olympics. The outer part of the market, the Jogai Shijo, that caters to the public will stay in its old place, but critics wonder about its chances for survival without the world's biggest fish trading place at its doorsteps. (Photo by Thomas Peter/Reuters)

Cool rider Ace on the back on the motorbike, on January 12, 2015, in Surabaya, Indonesia. A pair of dogs enjoy a bit of bark-and-ride – as they weave through Indonesiaís traffic on the back of a motorcycle. Wearing red-framed sunglasses and a helmet the two golden retrievers happily sandwich their owner on the fast bike. Unsurprisingly, the sight of the docile dogs hitching a fast ride in Surabaya, Indonesia, attracts a lot of attention from onlookers. Ace and Armani have been riding since they were just a few months old and now at the age of three the pair jump onto the bike whenever they think their owner is heading out. (Photo by Jefta Images/Barcroft Media/ABACAPress)

Japanese artist Megumi Igarashi, known as Rokudenashiko, holds her artwork after a news conference following a court appearance in Tokyo April 15, 2015. A Japanese artist on trial for obscenity after making figurines and a kayak modeled on her v*gina said on Wednesday that there was nothing wrong with her artwork and her arrest merely showed how far Japan remains behind the west. Words in the artwork read “Centre. 3D scan”. (Photo by Toru Hanai/Reuters)

Honda MotoGP rider Dani Pedrosa (R) of Spain sprays champagne on an attendant next to Yamaha MotoGP rider Valentino Rossi (C) of Italy after winning the Japanese Grand Prix at the Twin Ring Motegi circuit in Motegi, north of Tokyo, Japan, October 11, 2015. Rossi placed second. (Photo by Issei Kato/Reuters)

Actors perform the living Nativity biblical scenes in Postojna cave in Postojna, Slovenia, December 22, 2015. (Photo by Srdjan Zivulovic/Reuters)

An alert-looking Maine Coon during the Grand Prix Royal Canin cat exhibition in Moscow, Russia on December 4, 2016. The breed’s origin is unknown, but one legend claims it is descended from cats brought to the US by an English seafarer called Captain Coon. (Photo by Dmitry Serebryakov/TASS)

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)