Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

American rapper Saweetie and Quavo seen leaving Boa Steakhouse in West Hollywood, CA. on July 19, 2020. The couple appeared to enjoy dinner and posted a pda filled Instagram story at the restaurant. Saweetie and Quavo looked stylish as they made their way to their car. (Photo by Backgrid USA)

Poisoned River. Abstract Winner. A detailed photograph of a stream filled with poison. “Poisoned Beauty” is a personal project that tells the story of the natural disaster in the Apuseni Mountains in Transylvania, which was a result of chemical waste generated by copper and gold mining, but in a beautifully abstract way. (Photo by Gheorghe Popa/Drone Photography Awards 2021)

“«Pirate radio» in the UK first became widespread in the early 1960s when pop music stations such as Radio Caroline and Radio London started to broadcast on medium wave to the UK from offshore ships or disused sea forts. At the time these stations were not illegal because they were broadcasting from international waters. The stations were set up by entrepreneurs and music enthusiasts to meet the growing demand for pop and rock music, which was not catered for by the legal BBC Radio services”. – Wikipedia

Photo: The “World in Action” team making a program about the pirate radio ship Caroline, filmed by Paddy Searle, and produced by Mike Hodges. The DJ being filmed is Robbie Dale, and Hodges is standing behind him. (Photo by James Jackson/Evening Standard/Getty Images). 6th September 1967

“The Daleks are a fictional extraterrestrial race of genetically manipulated mutants from the British science fiction television series Doctor Who. Various storylines portray them as having had every emotion removed except hate, leaving them with a desire to purge the Universe of all non-Dalek life. Collectively they are the greatest enemies of the series' protagonist, the Time Lord known as the Doctor. Their famous catchphrase is “Exterminate!”, with each syllable individually synthesised in a frantic electronic voice” – Wikipedia

Photo: Max Hardy, aged 6, stands by a street sign from the Doctor Who Experience as Dalek, from the cult television show Doctor Who watches him on April 16, 2011 in London, England. The Doctor Who Experience Exhibition is currently running at Kensington Olympia Two, celebrating the science fiction programme that was originally screened in 1963. (Photo by Matthew Lloyd/Getty Images for BBC Worldwide)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

A protester holds a sign in front of riot policemen during an anti-G20 demonstration through the streets of Nice on November 1, 2011 in Nice, France. Anti-G20 demonstrators are gathered in Nice ahead of the arrival of the world's top economic leaders for the G20 summit in Cannes on November 3rd and 4th. The leaders are expected to debate current issues surrounding the global financial system in the hope of fending off a global recession and finding an answer to the Eurozone crisis. (Photo by Christopher Furlong/Getty Images)