Sites in English:
http://www.tess-elation.co.uk/new-hom : Reviews, methods, Escher,
essays and a lot of articles. The very informative site of David Bailey.
www.tessellations.org : One of the two main sites dealing with tessellations.
All aspects of tessellations and their history. Galleries and workshops.
http://www.k4.dion.ne.jp/~mnaka/home.index.html :
Tessellation World of Makoto Nakamura, a really great "tiler" artist.
http://www.ozbird.net :
Periodic and non-periodic tilings, the inventive art of John A.L. Osborn.
https://www.kickstarter.com/projects/mathspace/tessellation-masters-puzzle-series :
Wooden puzzles with artwork from masters of mathematical art from around the world. Beautiful and particularly inventive puzzles.
http://www.mcescher.com/ : The Official M.C.Escher Website, published by the M.C.
Escher Foundation and the M.C. Escher Company B.V.
http://www.worldofescher.com/ : Stories, discuss M.C. Escher's works,
provide insight, and offer our high quality products promoting the intriguing work of Escher.
http://www.scottkim.com/ : Designer of visual thinking puzzles for web and
print.
http://mathforum.org/sum95/suzanne/tess.intro.html
: Tutorials and templates for making your own tessellations. Historical and geographical connections.
http://britton.disted.camosun.bc.ca/jbsymteslk.htm
: Activity links on symmetry and tessellations.
http://tessellation.info/ : Tessellation Database. Over 400 tessellations,
46 artists. The best site about the tessellation artists.
http://www.ics.uci.edu : A marvellous source for all those
who take an interest in geometric curiosities.
http://www2.iap.fr/users/esposito/ambigallery.html
: The site of an esthete of the writing.
http://www.ambigr.am : The new ambigram online magazine of Kai Hammond.