Spoiler Alert: those “impossible” stairways M.C. Escher drew in the 1950s still can’t be replicated in 3 physical dimensions, but this video makes a good job of teasing the proposition that they can be.
And this entry from the Snopes facebook page explains the background.
The wikipedia page for MC Escher includes a terrific list of sources and a very convenient set of links to Selected Works.
Escher on Instagram
Finally, if you like this sort of thing and don’t already know him, be sure to follow modern-day M.C. Escher Kevin Parry on instagram. @kevinbparry