Symmetry in nature

This website http://sixrevisions.com/web_design/symmetry-design/ explores how symmetry is found in nature and in the world around us: 
Symmetry creates balance, and balance in design creates harmony, order, and aesthetically pleasing results. It is found everywhere in nature, and is probably why we find it to be so beautiful. Symmetry is one of the fundamental principles in gestaltism, a human behavior theory that proposes that our mind naturally creates order and completeness in the things we see and encounter.

There are three types of symmetry: reflection (bilateral) mirrorer effect such as a butterfly, rotational (radial) such as the petals in a flower, and translational symmetry (repetitive design elements) where the elements are proportional to one another. Each can be used in design to create strong points of interest and visual stability.