more solar calendars

Ok, the other day I went into how you could set up markers for the solstices, equinoxes and the cross-quarter days.

That seems to have been popular in Britain and western Europe.

I the American Southwest, the natives did it differently.

They set up sun daggers.

https://en.wikipedia.org/wiki/Fajada_Butte

They started with a spot where sunlight coming thru a gap in a formation created a wedge shape spot of sunlight on a rock wall. Then they marked where the point was on the summer solstice. They placed petroglgyphs on the rock face to mark this.

Interesting solution to a "common" problem.