I stepped back for a better overall picture of the pattern. Two concentric circles, centered on the altar, one maybe ten meters in diameter, the other maybe eleven. The half-meter-wide annulus between the two circles was divided into quadrants by radial lines. I checked the sun and guesstimated—yes, the radial lines seemed roughly aligned with the cardinal points of the compass. Around the annulus there were an even dozen strange, angular symbols. Not burned, these, but formed from scores of small, white pebbles carefully aligned. I looked around—no, as I'd suspected, there wasn't an obvious source for those pebbles anywhere in the Puowaina park.