It symbolizes absolute enlightenment, strength, elegance, the universe, and the void; it can also symbolize the Japanese aesthetic itself. As an "expression of the moment" In Zen Buddhist painting, ensō symbolizes a moment when the mind is free to simply let the body/spirit create. i like it for this one.
Ten Great Moments in Graveling - #2. Landscape architect, Bernard Trainor, achieved this zen-like driveway using a combination of clean lines, carefully choreographed plantings and sandy-colored-gravel. Photo by Jason Liske.