Translated from NOS TV in the Netherlands:
Unknown work by M. C. Escher discovered
On the large piece of paper one can see the Italian town Montecelio. Escher used in making it, inter alia, templates, stamps and Japanese elements. Thus, according to the curator of the museum, this was already a peek into his future as an artist.
The Escher Museum speaks of a “valuable” discovery, because Escher never made prints of this. There is only one copy of and this has been acquired by the museum now.
The artwork was in the possession of Escher’s family, but no one besides them knew of its existence.
See also here.
This video is about museums in the Netherlands.