Quadruple impossible staircase built by means of a paradoxal structure -a Tribute to Maurits Cornelis Escher- [Escalier quadruplement impossible construit à l'aide d'une structure paradoxale -un hommage à Maurits Cornelis Escher-].
(CMAP28 WWW site: this page was created on 11/22/2016 and last updated on 11/23/2022 12:38:02 -CET-)