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.

A rider demonstrates Lighting artist Bruce Munro latest installation “Star-Turn” at a one-night event in front of the Holburne Museum on December 21, 2011 in Bath, England. (Photo by Matt Cardy/Getty Images)

MTV's “Ex On The Beach” star Jemma Lucy gives her neighbours an eyeful as she takes her bins out in her underwear in Manchester, UK on August 22, 2016. Jemma Lucy is well known in UK for her love of flashing more than a little bit of flesh on a night out. But the reality star took things a step further this week as she took out the bins wearing nothing but her bra and knickers. (Photo by XposurePhotos.com)

A workman smooths out the gravel near the base of British artist Alex Chinneck' latest sculpture “A bullet from a shooting star” on the Greenwich Peninsula in London on September 17, 2015. The 35-metre tall, upside-down electricity pylon overlooks the Canary Wharf financial district. (Photo by Leon Neal/AFP Photo)

Izzy Paskowitz helps Nixee Grace Chanowsky, 4, catch a wave Monday, August 18, 2014 at Wrightsville Beach, N.C. during the Annual Surfers Healing event for children with autism. Hundreds of people made their way to the beach to watch and cheer on the camp that was founded by Israel and Danielle Paskowitz. (Photo by Mike Spencer/AP Photo/The Star-News)

A coil-shaped Helix Nebula showing a fine web of filamentary “bicycle-spoke” features embedded in the colorful red and blue ring of gas. At 650 light-years away, the Helix is one of the nearest planetary nebulae to Earth. A planetary nebula is the glowing gas around a dying, Sun-like star. (Photo by Reuters/NASA)