My high school had them all over. A couple of the ones I remember: a narrow hallway to a storage closet was painted like the inside of King Tut's tomb; one of the stairwells had an MC Escher staircase.
I did one of SCIENCE!! in the chemistry classroom. (part of a team, not by myself, I'm not that talented)
Niels Bohr, the evolution of atomic models, the periodic table.
. . . it made certain tests kind of easy XD