Las Vegas in 3 days: the Mojave Desert city that went from a railroad watering stop to the world's highest-grossing casino strip in 70 years, where 1,200 synchronized fountain jets choreograph to Frank Sinatra over an artificial lake, where 250 glowing casino signs rust in an outdoor museum of American neon history, and where the largest reservoir in the United States evaporates faster than the Colorado River can fill it.