We discovered this lovely dry stone wall in California yesterday. Actually it was a pattern formed by the cracks in the rocky shore bedrock exposed at low tide near Mendocino.
There are many similar patterns along the mile or so of beach we walked. I can't help but think that the structural configurations of proper dry stone walls built in a seemingly random way are to some degree as inevitable and as predictable as these kind of crack designs in rocks, which like the varied intricate designs of living plants can be generated and reproduced merely by applying the proper fractal functions.
I added small pebbles for coping.