A worker prepares the “Cutter Head” of the Port Tunnel boring machine for attachment to the tunneling machine on September 1, 2011 in Miami, Florida. The $45 million machine is longer than a football field and about as tall as a four-story building and it will carve the twin tunnels connecting Watson Island and Dodge Island. The the new $1 billion Port of Miami tunnel is expected to be completed in May of 2014. (Photo by Joe Raedle/Getty Images)

In this handout image provided by the Police of Swiss canton Valais the wreckage of a bus is seen after it crashed inside a motorway tunnel on March 13, 2012 in Sierre, Switzerland. 28 people, including 22 children, returning from a skiing holiday died in this bus accident. (Photo by Police Cantonale Valaisanne via Getty Images)

“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)

Palestinians and Israelis enjoy the Mediterranean sea during the first day of the Eid al-Fitr holiday in Tel Aviv, Israel, Thursday, August 8, 2013. The three-day Eid al-Fitr holiday marks the end of the holy fasting month of Ramadan. One of the most important holidays in the Muslim world, Eid al-Fitr, is marked with prayers, family reunions and other festivities. (Photo by Oded Balilty/AP Photo)

Palestinian schoolboys sit in the trunk of a car as they go to school on a rainy day in Khan Younis, in the southern Gaza Strip, October 7, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

A Palestinian horseman rides on the beach at sunset a few hours prior to the new year's celebrations, west of in Gaza city on December 31, 2018. (Photo by Mahmud Hams/AFP Photo)

Palestinian men perform fire breathing on the beach as an entertainment for children during the summer vacation in Gaza City on August 1, 2019. (Photo by Mohammed Abed/AFP Photo)

Palestinian children warm themselves by a fire on a stormy day at Shati (beach) refugee camp in Gaza City January 18, 2016. (Photo by Mohammed Salem/Reuters)