I think everyone probably remember MAD Magazine, and in particular the inside back cover, which often had a picture which would fold-in to form a new unexpected picture.

I talk about how to use this concept in gaming, especially used on a sea adventure ...

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Related Goblin's Henchman's Mad Map blog post: 

https://goblinshenchman.wordpress.com/2019/03/26/tuesday-toot-mad-magazine-map-musings/

Riddling Reaver, Voyage of the Enigma (Purple Worm padcast)

https://anchor.fm/purple-worm/episodes/Riddling-Reaver--Voyage-of-the-Enigma-eadqmt