A black gibbon is seen in a cage before being released into the wild by Indonesian nature conservation agency (BKSDA) in Jantho forest, Aceh province on August 26, 2021. (Photo by Chaideer Mahyuddin/AFP Photo)

A man prepares to tie a black ribbon next to a makeshift memorial during a prayer ceremony for the victims of the 2004 tsunami on the 16th anniversary of the disaster, at Marina Beach in Chennai, India, December 26, 2020. (Photo by P. Ravikumar/Reuters)

A boy and a serviceman pose for a picture during Marines Day celebration in the Black Sea port of Sevastopol, Crimea, November 27, 2016. (Photo by Pavel Rebrov/Reuters)

Scarlett Johansson, Florence Pug, Rachel Weisz and David Harbour star in the action spy thriller “Black Widow”. Pictured: English actress Florence Pugh as Yelena. (Photo by Splash News and Pictures)

American singer-songwriter Katy Perry in the second decade of June 2024 posed in a white bra top with heavy black metallic leg armour to announce her new single Woman’s World. (Photo by Katy Perry/Instagram)

“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)

A Romanian female soldier adjusts her helmet before taking part in weapons training with US Marines female counterparts at the Capu Midia Surface to Air Firing Range, on the Black Sea coast in Romania, Monday, March 20, 2017. About 1,200 US and Romanian troops take part in the Spring Storm 17 exercise, meant to simulate defense of the Romanian Black Sea coastline and urban areas. (Photo by Vadim Ghirda/AP Photo)

A police officer who was injured when falling of a horse during scuffles with demonstrators at Downing Street during a Black Lives Matter march in London, Saturday, June 6, 2020, is dragged by colleagues, as people protest against the killing of George Floyd by police officers in Minneapolis, USA. Floyd, a black man, died after he was restrained by Minneapolis police while in custody on May 25 in Minnesota. (Photo by Frank Augstein/AP Photo)