Fighters from Germany take up position before competing in the Medieval Combat World Championship at Malbork Castle, northern Poland, April 30, 2015. Medieval combat is a full contact sport that revives the foot based tournament fighting of medieval Europe. Countries fight in refereed matches where the objective is to get the opposing team to the floor. There are also duels with polearms, swords and shields where the number of hits landed are scored. The fighters, both male and female, wear heavy armours and weapons, mostly replicas of authentic pieces, and fight following the knights code of conduct. According to organizers, 25 nations from 6 continents are taking part in the Championships, which started on April 30 and will go on until May 3. (Photo by Kacper Pempel/Reuters)

“Dover Castle is a medieval castle in the town of the same name in the English county of Kent. It was founded in the 12th century and has been described as the “Key to England” due to its defensive significance throughout history. It is the largest castle in England.

The outbreak of the Second World War in 1939 saw the tunnels converted first into an air-raid shelter and then later into a military command centre and underground hospital. In May 1940, Admiral Sir Bertram Ramsey directed the evacuation of French and British soldiers from Dunkirk, code-named Operation Dynamo, from his headquarters in the cliff tunnels”. – Wikipedia

Photo: The Repeater Station in the subterranean tunnels underneath Dover Castle, which has been restored by English Heritage for a public exhibition on June 3, 2011 in Dover, England. The evacuation of allied soldiers from Dunkirk was masterminded and co-ordinated from the secret command and control centre in the tunnels deep below the castle. (Photo by Matthew Lloyd/Getty Images)

Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

The World Enduro Super Series roared back into life this weekend with Mario Roman coming out on top at the Toyota Porto Extreme XL Lagares on May 12 to stake an early claim for the title of Ultimate Enduro Champion 2019. The Spaniard beat the 300 competitors, including 50 pros, who entered Sunday's Hard Enduro feature race in the baking Portuguese heat. Here: Graham Jarvis and Billy Bolt race at Toyota Porto Extreme XL Lagares, Portugal on May 12, 2019. (Photo by Future7Media/Red Bull Content Pool via AP Images)

Artist Vik Muniz is known for his gigantic composite installations and sculptures created from thousands of individual objects. In this new collaboration with artist and MIT researcher Marcelo Coelho, Muniz takes the opposite approach and explores the microscopic with a new series of sandcastles etched onto individual grains of sand.

ne committed photographer spent a grand total of 3,000 dive hours trying to get the perfect shots, capturing beautiful images of a rare shark feeding frenzy. Laurent Ballesta’s images show the glimmering gray reef sharks hunting in swift packs, flying through the water and feasting on the likes of helpless grouper. (Photo by Laurent Ballesta/Caters News Agency)

The Tree Projects team spent 67 days documenting one eucalyptus regnans in the Styx valley of Tasmania. Using a combination of tree-climbing and elaborate arboreal rigging techniques, they produced an intimate portrait from an impossible perspective of one of the world’s largest individual flowering trees, which goes by several common names. These photos document the process that resulted in an extraordinary ultra high-definition photograph. Here: Haley nears the top of the tree. (Photo by Steven Pearce/The Tree Projects/The Guardian)

A policeman controls traffic at 42nd Street and 7th Avenue as New York City remains without electricity caused by a blackout that affected the entire city and most of the eastern part of the nation August 15, 2003 in New York, New York. More than 50 million people were affected by the outage, in Toronto, Detroit, Cleveland and New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images)