The architect Christopher Alexander tells this story in The Timeless Way of Building:
I once saw a simple fish pond in a Japanese village which was perhaps eternal.
A farmer made it for his farm. The pond was a simple rectangle, about 6 feet wide, and 8 feet long; opening off a little irrigation stream. At one end, a bush of flowers hung over the water. At the other end, under the water, was a circle of wood, its top perhaps 12 inches below the surface of the water. In the pond there were eight great ancient carp, each maybe 18 inches long, orange, gold, purple, and black: the oldest one had been there eighty years. The eight fish swam, slowly, slowly, in circles—often within the wooden circle. The whole world was in that pond. Every day the farmer sat by it for a few minutes. I was there only one day and I sat by it all afternoon. Even now, I cannot think about it without tears. Those ancient fish had been swimming, slowly, in that pond for eighty years. It was so true to the nature of the fish, and flowers, and the water, and the farmers, that it had sustained itself for all that time, endlessly repeating, always different. There is no degree of wholeness or reality which can be reached beyond that simple pond.