Maurits Cornelis Escher, known by its initials, MC Escher (born 17 June 1898 - d. 27 March 1972) was an artist, engraver and illustrator from the Netherlands . He lived for many years in The Hague, where a museum was opened in his honor, the Escher Museum.
His most famous works have as a starting point impossible objects and optical illusions.
Our question is: what famous Mathematical object can you see in this drawing?
The official Escher site is here.