Site · Egypt and Nubia · Egypt
Great Pyramid of Khufu (G1)
Four sides of Khufu's pyramid, each about 230 m long, differ by just 4.6 cm
c. 2600-2560 BCE (4th Dyn.)
Several methods could find north this precisely. Which one fits the stones best, and what would it tell us about how the builders watched the sky?
Photo: Douwe C. van der Zee, CC BY-SA 4.0, Wikimedia Commons