The Thing? is an Arizona roadside attraction hyped by signs along Interstate 10 between El Paso, Texas, and Tucson, Arizona. Teaser ads, such as The Thing? What is it? and Mystery of the Desert, entice travelers along this sparse stretch of desert highway to pull in just to find out what the mysterious Thing? might be. Such billboards are similar to signage seen in the South as drivers approach the South of the Border near Dillon, South Carolina and Rock City near Chattanooga, Tennessee.