{3,6} tessellation of the Euclidean plane

 

{4,4} tessellation of the Euclidean plane

 

{6,3} tessellation of the Euclidean plane

 

{5,4} tessellation of the Poincaré disk

 

Another illustration of the {5,4} tessellation of the Poincaré disk

 

{6,4} tessellation of the Poincaré disk

 

{8,4} tessellation of the Poincaré disk

 

Escher's "Angel-devil" drawing illustrates
a {4,4} tessellation in Euclidean geometry

 

Escher's "Heaven and Hell" wood carving illustrates
a {4,3} tessellation in spherical geometry

 

Escher's "Circle Limit IV" illustrates
a {6,4} tessellation in hyperbolic geometry

 

A tiling of the hyperbolic plane by black and white triangles.
This tiling exhibits a great deal of regularity, but it does not fit
our technical definition of a "regular tessellation"

 

Escher's Circle Limit I

 

Escher's Circle Limit II