People are seen on a street in Havana December 17, 2014. Stunned Cubans celebrated an apparent end to decades of conflict with the United States on Wednesday after both governments said they would restore diplomatic relations cut off in 1961. Many said they expected a restoration of ties would lead to the end of a U.S. economic embargo against Cuba, which is vilified daily in the official media and which Cubans accept as a key cause of widespread poverty on the island. (Photo by Reuters/Stringer)

“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)

Nestled among the cocoa plantations of western Ivory Coast is a gold mine that does not feature on any official maps. It is not run by an industrial mining company, nor does it pay taxes to the central government. The unlicensed mine is a key part of a lucrative business empire headed by the deputy commander of the West African nation's elite Republican Guard, United Nations investigators allege. Here: A gold prospector sits and eats close to a soldier at a gold mine near the village of Gamina, in western Ivory Coast, March 18, 2015. (Photo by Luc Gnago/Reuters)

A mechanic examines a Gogoro Smartscooter which is connected to a tablet, in its shop in Taipei, Taiwan, July 6, 2015. Companies such as electric motor scooter firm Gogoro could hold the key to Taiwan's economic growth. In just three years, the start-up raised $150 million to develop the smartphone-synched bike, and a charging network for it. Gogoro's success in creating a home-grown, innovative product is precisely what Taiwan's government wants to foster as it seeks to reduce the export-driven economy's reliance on the island's world-class tech manufacturing sector. (Photo by Pichi Chuang/Reuters)

Chief priest Gbenga Saala raises a cutlass to kill a dog during an annual prayer and sacrifice celebration of the iron god Ogun in Abuja, Nigeria, June 23, 2015. Every year worshippers offer a dog as sacrifice to Ogun, a traditional Nigerian deity, in hope of an auspicious year ahead. Taxi drivers, blacksmiths, panel beaters and mechanics – trades that depend on metal for their livelihood – pay homage to Ogun, led by high priest Gbenga Saala. As part of the ceremony, the priest pours the dog’s blood on symbols of these workers’ trade: keys, spanners and other tools piled up in a metal barrel. (Photo by Afolabi Sotunde/Reuters)

“The Great Barrier Reef is one of the most important sea turtle habitats in the world, with Lady Elliot Island being a key part of that habitat. Every year between November and March the green and loggerhead turtles lumber up the same beach on which they were born more than 50 years ago. These turtles nest on Lady Elliot Island up to nine times in a season, laying between 80 and 120 eggs per clutch. About eight weeks later, young hatchlings leave their nests and head towards the ocean (January to April)”. – Wikipedia

Photo: A Hawksbill sea turtle is seen swimming on January 15, 2012 in Lady Elliot Island, Australia. (Photo by Mark Kolbe/Getty Images)

Crew in Britain's first ever full-size reconstructed sea-going Bronze Age boat, paddle out to sea near to the National Maritime Museum as it makes its maiden voyage on March 6, 2013 in Falmouth, England. (Photo by Matt Cardy)

Keith Haubrich of Seattle, Wash., reacts to the crowd while competing in the Dali Moustache division during the fourth annual Just For Men National Beard and Moustache Championships Saturday, September 7, 2013 in New Orleans. Haubrich went on to win the gold medal for the Dali division.Contestants competed in 18 different categories including Dali, full beard natural and sideburns.(Photo by Susan Poag/AP Photo)