Fort Bourtange is a star fort located in the village of Bourtange, Groningen, Netherlands. It was built in 1593 under the orders of William the Silent. Its original purpose was to control the only road between Germany and the city of Groningen, which was controlled by the Spaniards during the time of the Eighty Years' War.

Climbers ascend the walls of the Westway Climbing Centre on June 15, 2011 in London, England. The Westway indoor climbing centre is located under the A40 flyover in Shepherd's Bush has over 350 climbing routes, some of which rise to over 14 meters. (Photo by Oli Scarff/Getty Images)

Shemika Charles limbos under her car at Niagara Falls State Park on May 28, 2015 in Buffalo, New York. A world record holding limbo queen thinks she has become the first person to shimmy under a car. Shemika Charles amazed herself and onlookers when she bent over backwards to get underneath the SUV earlier this week. The supple 22-year-old entered the record books in 2010 when she limboed down to an incredible eight and a half inches – the height of a beer bottle. She trains for up to four hours a day to keep her body in peak condition and now travels around America performing with her family. However, regular performances put an incredible strain on her body and she sees a chiropractor once a week to have her hips realigned. Her mother was also a successful limbo dancer in her home country of Trinidad and Tobago but had to give up due to injury. (Photo by Ruaridh Connellan/Barcroft USA)

The Boeoegg, a giant symbolic snowman made of wadding and and filled with firecrackers burns on top of a bonfire in Sechselaeuten square on April 24, 2017 in Zurich. When the bells of the Saint Peter's church chime six o'clock, the bonfire under the snowman is set in fire and the guildsmen wearing historical costumes ride around the bonfire. The faster the head of the snowman explods the warmer and more beautiful the summer will be. (Photo by Michael Buholzer/AFP Photo)

Up to 35% of Mongolians still live a nomadic life, depending on their land to survive. But environmental changes, particularly desertification, means this way of life is under threat. Korean photographer Daesung Lee’s Futuristic Archaeology images show billboard-size backdrops of lush steppe contrasting with actual scenery as former nomads enact scenes of hunting, herding and Mongolian wrestling. (Photo by Daesung Lee)

A team of Irish dancers celebrate after winning the under 12's group kaylee World Irish Dance Championship on April 2, 2016 in Brighton, England. The 8th World and 11th European Irish Dance Championships sees over 1500 dancers from 26 countries, speaking over 20 languages, competing in a variety of contests at the Brighton Centre on the city's beachfront. The event is organised by the World Irish Dance Association and is billed as the “Irish Dance Spectacular”. (Photo by Chris Ratcliffe/Getty Images)

A boy crawls under a cow during a religious ceremony celebrating the Tihar festival, also called Diwali, in Kathmandu, October 23, 2014. Hindus all over Nepal are celebrating the festival during which they worship cows, which are considered a maternal figure, and other animals. Also known as the festival of lights, devotees worship the goddess of wealth Laxmi by illuminating and decorating their homes using garlands, oil lamps, candles and colourful light bulbs. (Photo by Navesh Chitrakar/Reuters)