Pi Line Promontory

Coordinates: U31 (At the edge of the mountains east of the river)
In Brief: On a high ledge there is a curious graffito on a smooth rockface.
Owner(s): WolphStrykes and Gamina
Current Staff: None; self-guided
Features: A vignette plays out while you watch.
Beds: No
Why? There is a puzzle or riddle of a mathematical nature to reason out.