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)

A view of one of the dioramas contained inside iron boxes as part of the “S.A.C.R.E.D” installation by Chinese artist Ai Weiwei during a media preview at the cathedral in Cuenca, Spain, July 21, 2016. Ai Weiwei has reproduced scenes of his incarceration for a new art installation, a series of almost life-size dioramas – encased in steel boxes – showing his life in jail. (Photo by Susana Vera/Reuters)

Nguyen Manh Quan (top), 26, a civil servant, carries a girl using his throat area as he performs during a showcase of the traditional Thien Mon Dao kung fu at Du Xa Thuong village, southeast of Hanoi, Vietnam May 10, 2015. Thien Mon Dao, a traditional Vietnamese martial art, was formed by 18th century villagers in Du Xa Thuong village, who believed the art form could help improve health as well as fight against foreign invaders. There are currently about 3,000 practitioners including farmers, industry workers and state servants. These practitioners say they are able to bend metal against their bodies and carry heavy objects using their throats, eyes or tongues, as well as run across the surface of a river, according to Thien Mon Dao kung fu master Nguyen Khac Phan. (Photo by Reuters/Kham)

This graceful husky appears to be smarter than your average dog having apparently mastered the art of walking on water. The soft-footed canine was photographed while making its way across a lake in northern Russia. Photographer Fox Grom captured a remarkable set of images after heavy rain fell on a frozen lake to create the amazing illusion. The 40-year-old, who works as an all-terrain vehicle driver, regularly walks his pet dogs, Alaska and Blizzard, near the natural beauty spot. “I always take pictures of my dogs whilst walking them but on this occasion there was an extraordinary phenomenon“, he said. “The ice was already very thick when it rained heavily making for a spectacular scene”. Here: Husky dog Alaska walks on water in Northern Russia, January 2015. (Photo by Fox Grom/Visual Press Agency)

In this March 15, 2012 file photo, a Chinese woman poses for photos near a sculpture depicting a Chinese yuan note at an art district in Beijing, China. China devalued its tightly controlled currency on Tuesday, August 11,2015, following a slump in trade, triggering the yuan's biggest one-day decline in a decade. The central bank said the yuan's 1.3 percent fall was due to a change aimed at making its exchange rate controls more market-oriented. But any change raises the risk of tensions with China's trading partners. (Photo by Ng Han Guan/AP Photo)

Dressers make last minute adjustments to the costumes of dancers performing as horses during a press preview of American artist Nick Cave's first major work shown in Australia, entitled HEARD.SYD in Sydney, November 8, 2016. Over several days the live art performance will feature 30 “horses” dancing to live percussion beats in suits made from coloured raffia plant fibres. (Photo by Jason Reed/Reuters)

Jose Sabas Gomez pastes eyelashes to a statue of El Jesus Nazareno in his workshop in Apastepeque, El Salvador March 9, 2016. Sabas is one of a small number of artists still working on traditional religious art in El Salvador. According to him, there used to be more workshops engaged in the work of restoring statues of saints, but only four remain today as the labor-intensive craft is no longer a popular choice of profession. (Photo by Jose Cabezas/Reuters)

There are many types of hobbies. Some of them are strange, such as piercing your skin with huge metal hooks with ropes attached to them, and dangling yourself from the ceiling. Others might enjoy riding down huge mountain hills on skis, snowboards, mountain boards, bikes, etc. However, some enjoy pastimes that are more tranquil and meditative. For example, the art of contortionism is a very peculiar hobby that is usually practiced by women and children, due to the natural stretchiness of their tendons. Despite the fact that tendons of grown men are usually too stiff, a Berlin-based dancer is able to do amazing things with his body and is not afraid to show it to the world.