Across Egypt, traces of unfinished megalithic work still sit frozen in place, reminders of techniques we only partly understand. From the casing stones of Menkaure’s pyramid to the megalithic granite walls of the Osirion, you see sweeping scoop marks, half-shaped surfaces, and massive stones left in various stages of work. In the Serapeum, an enormous block still lies unfinished and apparently abandoned where it was last left, offering another hint at how these monuments were formed. Traces like