A decorative knot with 20-crossings and five-fold rotational symmetry (a variation on a design in George Bain's Celtic Art: The Methods of Construction, but made with circular arcs and straight lines only).  For a version with three-fold symmetry, see File:12crossing-decorative-knot-triskele.svg.
Self-made image, converted from a version of the following vector PostScript source code:

%!
306 396 translate/x 93.2 def/y 90 def
5{194.15 100 x sub x -72 90 arc
-72.6542528 100 y add y 270 -18 arcn
-11.521 18 sin mul -11.521 18 cos mul rlineto
stroke 144 rotate}repeat showpage
%EOF
AnonMoos