The stones show the point on the horizon where the sun rises at the vernal blot. The distance between the stones is 29 m.
The animation shows the vernal blot based on the spring equinox as defined by 1) Height Model Equinox and 2) Refraction Equinox. See definitions in Days-of-the-calendar.
The gradient of the top of the highest stone is in good alignment with the sun’s path. The sun’s path is exactly right a half moon cycle after the spring equinox, defined as the day before spring equinox according to today’s definition (“refraction equinox”).
Forest obscures the sun at sun rise.