In 1917, two young cousins returned from the creek behind their house with thrilling news: they had photographed fairies! Their parents were skeptical, but soon the photos of the "Cottingley Fairies" were circulated, eventually finding a champion in Sir Arthur Conan Doyle.   

Sources:
 ‘Fairies Photographed: An Epoch-Making Event.’ Strand Magazine, 1920
'The Coming of the Fairies' by Arthur Conan Doyle (London: Hodder & Stoughton)
‘That Astonishing Affair of the Cottingley Fairies,' by G. Crawley. British Journal of Photography
https://journal.sciencemuseum.ac.uk/article/power-at-play-in-paranormal-history/ 
https://www.laphamsquarterly.org/roundtable/father-and-son-who-believed-faeries