A soldier under Russian command restrains a colleague after he fired his weapon into the air and screamed orders to turn back at an approaching group of over 100 unarmed Ukrainian troops at the Belbek airbase, which the Russian troops are occcupying, in Crimea on March 4, 2014 in Lubimovka, Ukraine. (Photo by Sean Gallup/Getty Images)

South Korean teenagers participate in a warfare exercise as part of the Special Warfare Command's training course at a military base on August 4, 2011 in Seoul, South Korea. About 1,000 civilian volunteers including middle and high school students participated in the special force's four-day training programme to develop their spiritual and physical strength. (Photo by Chung Sung-Jun/Getty Images)

Commander of the Joint Forces of the Armed Forces of Ukraine Serhiy Nayev holds puppies as he visits at positions near the border with Belarus, amid Russia's attack on Ukraine, in Zhytomyr region, Ukraine on September 20, 2023. (Photo by Gleb Garanich/Reuters)

Sergeant Andrew Garrett watches K-Dog, a bottlenose dolphin attached to Commander Task Unit 55.4.3, leap out of the water while training near the USS Gunston Hall March 18, 2003 in the Persian Gulf. (Photo by U.S. Navy/Getty Images)

Figurines of former pro-Russian separatist commander Igor Strelkov from the collection entitled “Toy Soldiers of Novorossiya” are on display at a workshop in Moscow August 29, 2014. A Moscow-based maker of toy soldiers has sought inspiration for his creations from Ukrainian rebels fighting government troops in the east of Ukraine. Toy soldier maker, Timur Zamilov, displayed his new collection of rebel fighters cast in metal on Friday, before they are due to go on sale. His new collection is entitled “Toy Soldiers of Novorossiya” (New Russia), a reference to regions in eastern Ukraine where pro-Russian separatist fighters want full independence. Zamilov's selection includes models of Cossack soldiers, volunteers, soldiers bearing anti-aircraft missiles and even a miniature of prominent rebel leader Igor Strelkov. (Photo by Sergei Karpukhin/Reuters)

A soldier of the Household Cavalry Mounted Regiment falls off a horse during a practice to participate in the state ceremonial surrounding this year's Platinum Jubilee celebrations at Hyde Park in London, Thursday, March 31, 2022. Around 170 horses and personnel of the Household Cavalry Mounted Regiment left their Hyde Park Barracks to form up and be inspected by the General Officer Commanding the Household Division, Major General Christopher Ghika. (Photo by Frank Augstein/AP Photo)

A boy sits next to sacrificial goats resting during Eid al-Adha in New Delhi, India, 29 June 2023. Muslims around the world celebrate Eid al-Adha or feast of sacrifice, by slaughtering sheep, goats and cows to commemorate Prophet Abraham's willingness to sacrifice his son Ismail at God's command. (Photo by Harish Tyagi/EPA)

“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)