For decades, the Nile Valley was a classic destination for American travelers. If you had the means, it was a place you simply had to see. Even though the crowds at the pyramids might have been oppressive, the structures themselves were still astounding. The Great Pyramid of Khufu was the tallest man-made structure on earth for nearly 4,000 years (in fact until the completion of Lincoln Cathedral in England in 1311). And ancient Egyptian civilization was incomparable: From the founder of the First Dynasty, Narmer, to the death in 343 B.C. of Nectanebo II, the last pharaoh of the Thirtieth Dynasty, it endured, astonishingly, for some 2,750 years.