"Birds make their nests in circles, for theirs is the same religion as ours.
The sun comes forth and goes down in a circle.
The moon does the same and both are round.
Even the seasons form a great circle in their changing and always come back again to where they were.
The life of a man is a circle from childhood to childhood and so it is in everything where power moves.
Our tepees were round like the nest of birds and these were always set in a circle."
Black Elk (Lakota Holy Man)