Mandala is from the Sankrit for "Circle".  The Circle is the physical representation of Totality and of Oneness.  Circles have no beginning and they also have no end and so they are also representative of the Cycles of Life.  Physically and Spiritually, it is the representation of Sacred Space.  Physically, we can ~Circle~ any Space and make it Sacred.  Spiritually that ~Space~ is within us.

http://thejourneyinward.net/mandalas/mandala2.html

http://thejourneyinward.net/tableofcontents.html