A knight is placed on the empty chessboard and moves according to the rules of chess. For a knight's tour, the knight must visit each square exactly once. In these variants, boards with a wide variety of shapes are used instead of a standard chessboard. Some solutions present very beautiful designs.
Snapshot 1: a board for a variant of the knight's tour
Snapshot 2: a solution
Snapshot 3: a graph made from the problem
For the details of this article please see the following reference:
R. Miyadera et al, "Beautiful Designs Made from the Knight's Tour," Visual Mathematics: Art and Science Electronic Journal of ISIS-Symmetry (Sept 13, 2007).