Iraqi government forces are seen near the Falahat village west of Fallujah on June 27, 2016. Iraqi forces took the Islamic State group's last positions in the city of Fallujah on June 26, establishing full control over one of the jihadists' most emblematic bastions after a month-long operation. (Photo by Moadh Al-Dulaimi/AFP Photo)

A demonstrator kicks a riot police vehicle during an unauthorized march called by the Chilean student federations to protest against government's education reform, in Santiago, Chile July 5, 2016. (Photo by Ivan Alvarado/Reuters)

Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/Reuters)

Kurdish pesh merga troops fire at Islamic State positions as they move toward the Iraqi town of Badana Pichwk on Monday morning, October 17, 2016. Kurdish forces began Monday advancing on a string of villages east of Mosul, the start of a long-awaited campaign to reclaim Iraq's second-largest city from the Islamic State, which seized it more than two years ago, officials said. (Photo by Bryan Denton/The New York Times)

Dancers of the English National Ballet perform The Nutcracker at the Coliseum on December 14, 2011 in London, England. (Photo by Ian Gavan/Getty Images)

A member of a rival team walks during an annual carnival battle with oranges in the northern Italian town of Ivrea February 15, 2015. Dressed up as Middle Age kings' guards, a group of men ride in a horse-drawn carriage and pelt “foot soldiers” with oranges as thousands of people gather to re-enact a Middle Age battle when the townsfolk of Ivrea overthrew an evil king. In a strange twist, instead of swords and cross bows, these days the weapons of choice are oranges. (Photo by Max Rossi/Reuters)

Revellers take part in the annual “Naval Battle” of Vallecas in Madrid, Spain July 19, 2015. The slogan for this year's water battle is “Get wet for Alfon, freedom for Alfon”, referring to Alfonso Fernandez Ortega, a Vallecas resident who was sentenced to four years in prison in June. The festival was started spontaneously in 1981 when some neighbours started to throw water at one another due to high temperatures during the Virgen del Carmen Festival. (Photo by Juan Medina/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)