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 07/16/2019 and last updated on 07/16/2019 14:42:41 -CEST-)