Pyramids of Giza, Giza, Egypt, 1990

"Memorials to Egyptian kings, the pyramids of Giza still rise above the desert after 4,000 years. Builders may have used water-filled ditches as a check on levels. Stone—not sun-dried mud brick—promised permanence for these monuments, only survivors of the ancient world's classic seven wonders."

(From the National Geographic book Builders of the Ancient World: Marvels of Engineering, 1986)

(Photograph shot on assignment for, but not published in, "Ibn Battuta: Prince of Travelers," December 1991, National Geographic magazine)