Varying the length of three sides of a hyperbolic right angled hexagon - a Geogebra App.

Random walk in the Poincare disk.

Dissecting Hypercubes with Pascal's Triangle | Infinite Series

Coxeter explains the mathematics behind Escher hyperbolic paintings.

Klein quartic I, by Jos Leys

Klein quartic II also by Jos Leys

Dodecahedral tesselation of the hypersphere by Jos Leys