“1955 was a year of change for Marilyn Monroe. After leaving Hollywood for New York, and abandoning her contract with Twentieth Century Fox, Marilyn was no longer “just a dumb blonde”, but a true renegade. In January, Marilyn formed a production company with photographer Milton Greene, and moved into a suite at the Ambassador Hotel”...

Photo: American actress Marilyn Monroe (1926–1962) leans over the balcony of the Ambassador Hotel in March 1955 in New York City, New York. (Photo by Ed Feingersh/Michael Ochs Archives)

An aerial view shows a sinkhole 3.5 km (2 miles) to the east of Solikamsk-2 mine in Perm region, November 20, 2014. Shares in Russia's Uralkali, the world's top potash producer, fell sharply for a second day on Wednesday after a mine accident that could reduce global supplies and push up prices of the crop nutrient worldwide. Uralkali shares have fallen 28 percent since Tuesday when it suspended work at its Solikamsk-2 mine, which accounts for a fifth of the company's output and 3.5 percent of global capacity, following an inflow of water. A sinkhole, stretching 30 by 40 metres (yards), found at an abandoned mine 3.5 km (2 miles) to the east, increased concern about the future of the mine because an inflow of water and the resulting sinkhole in 2006 forced another Uralkali operation to shut permanently. (Photo by Reuters/Press service of Uralkali company)

Emma the Maltese's fur blows in the wind as she rides in her owner's purse on 5th Avenue at Central Park in New York December 2, 2014. (Photo by Carlo Allegri/Reuters)

Austrian alpine skiers (LtoR) Georg Streitberger, Klaus Kroell, Max Franz, Joachim Puchner, Romed Baumann pose in the Olympic Rings on February 4, 2014 at the Mountain Olympic Village at the Rosa Khutor Alpine centre, four days prior to the start of the 2014 Sochi Winter Olympic Games. (Photo by Fabrice Coffrini/AFP Photo)

“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)

Festival goers attend day one of the Parklife Festival at Heaton Park on June 9, 2018 in Manchester, England. (Photo by Mercury Press)

Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

A woman greets a street artist at the San Fermin festival in Pamplona, northern Spain July 8, 2016. (Photo by Eloy Alonso/Reuters)