1974: American boxer Muhammad Ali, formerly Cassius Clay, strikes an aggressive pose at a press conference on November 29, 1974. (Photo by Harry Dempster/Express/Getty Images); American actor Will Smith at the Royal Premiere of the film Ali in London on December 11, 2001. Smith starred as Muhammad Ali in the film. (Photo by Dave Hogan/Getty Images)

Museum employee Victoria views a giant grouper fish specimen at the Natural History Museum in west London March 25, 2015. It forms part of a new exhibition, “Coral Reefs: Secret Cities of the Sea”, featuring a panoramic virtual dive and over 250 specimens from the Museum's coral, fish and marine invertebrate collection, which opens on March 27. (Photo by Toby Melville/Reuters)

Members of staff makes last minute touch ups of wax figure Chewbacca, from Star Wars, on display at “Star Wars At Madame Tussauds” on May 12, 2015 in London, England. (Photo by Stuart C. Wilson/Getty Images)

David Bowie, 1974. David Bowie's quirky character and style was perfectly encapsulated in this shot by Terry O'Neill, which shows the music legend posing next to a barking dog on the artwork for his 1974 album “Diamond Dogs” in London. (Photo by Terry O'Neill)

British-based Ukrainians gather outside the Russian Embassy in London to protest against the build-up of troops in the Crimea region, on March 2, 2014. The demonstrators chanted and held banners demanding “Hands off Ukraine”. (Photo by John Stillwell/PA Wire)

A workman smooths out the gravel near the base of British artist Alex Chinneck' latest sculpture “A bullet from a shooting star” on the Greenwich Peninsula in London on September 17, 2015. The 35-metre tall, upside-down electricity pylon overlooks the Canary Wharf financial district. (Photo by Leon Neal/AFP Photo)

It’s enough to make your head spin. The photographer Katherine Young set out to shoot spiral staircases in London, England to great effect, including this shot she calls the Downward Spiral Part III. (Photo by Katherine Young/Rex Features/Shutterstock)

Employee Jenny Forgie works on an orchid display at Kew Gardens in London, Thursday, February 8, 2018. The 23rd annual Orchid Festival is the first one with a Thailand theme, 66 volunteers worked on the 6,950 exhibited orchids. The festival is open from Feb. 10, 2018 until March 11, 2018. (Photo by Frank Augstein/AP Photo)