The most fabled city in ancient Arabia was Ubar, described in the Koran as "the many-columned city whose like has not been built in the entire land." But like Sodom and Gomorrah, Ubar was destroyed by God for the sins of its people. Buried in the desert without a trace, it became known as "the Atlantis of the Sands." Over the centuries, many searched for it unsuccessfully, including Lawrence of Arabia, and skepticism grew that there had ever been a real place called Ubar. Then in the 1980s Nicholas Clapp stumbled on the legend. Poring over ancient manuscripts, he discovered that a slip of the pen in a.d. 1460 had misled generations of explorers. In satellite images he found evidence of ancient caravan routes that were invisible from the ground. Finally he organized two expeditions to Arabia with a team of archaeologists, geologists, space scientists, and adventurers. After many false starts, dead ends, and weeks of digging, they uncovered a remarkable walled city with eight towers, thi