A spring breaker takes a shot of tequila during a pool party at a hotel in Cancun March 8, 2015. Like previous Florida spring break hot spots Fort Lauderdale and Daytona Beach, Panama City Beach is facing a crisis of conscience over the trade-offs involved in hosting a binge for some 300,000 students who arrive through mid-April with coolers, beer funnels and credit cards. (Photo by Michael Spooneybarger/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)

“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)

This photo provided by NASA shows a full moon rising behind the United Launch Alliance Atlas V rocket with NASA's Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft onboard at the Cape Canaveral Air Force Station Space Launch Complex 41, Sunday, November 17, 2013, Cape Canaveral, Florida. NASA's next Mars-bound spacecraft, the Mars Atmosphere and Volatile Evolution, or MAVEN, is the first spacecraft devoted to exploring and understanding the Martian upper atmosphere. (Photo by Bill Ingalls/AP Photo/NASA)

One of two 9-month old Cheetahs is seen after it was released into a quarantine facility at Zoo Miami on November 29, 2012 in Miami, Florida. The two sub-adult brothers who arrived today were captive-born on March 6th of this year at the Ann van Dyk Cheetah Centre just outside of Pretoria, South Africa. The Cheetahs, after being monitored and examined for a minimum of 30 days to insure that they are healthy and stable, will be featured in Zoo Miami's Wildlife Show at the newly constructed amphitheater and will continue the work of Zoo Miami's Cheetah Ambassador Program by making appearances off Zoo grounds at a variety of venues including schools and civic organizations. (Photo by Joe Raedle)

Fireworks light the morning sky March 6, 2012 as the Disney Fantasy, the newest Disney Cruise Line ship, arrives in her home port of Port Canaveral, Florida after traveling nearly 4,700 miles across the Atlantic Ocean from Bremerhaven, Germany. The 4,000-passenger Disney Fantasy will welcome guests on her maiden voyage on March 31, 2012, sailing seven-night cruises to the Caribbean and Disney's private island Castaway Cay, from Port Canaveral. (Photo by Todd Anderson/Disney Parks via Getty Images)