The Secrets of Engineering and the Splendor of the Achaemenid Empire | How Persepolis Survived 2,500 Years

The creation of Persepolis began with an extraordinary feat of civil engineering: the leveling of an immense stone terrace covering about 125,000 square meters. Builders carved into the mountain, filled depressions with compacted rubble, and raised colossal retaining walls. The precision of their stonework remains astonishing; blocks fitted together so tightly that no mortar was required, secured only with metal clamps shaped like swallowtails. This level platform, rising nearly 12 meters above the plain, became the canvas for an architectural masterpiece.