Vail is a census-designated place in Pima County, Arizona, United States. It is 24 miles southeast of Tucson. The population was 10,208 at the 2010 census, up from 2484 in the 2000 census. The area is known for the nearby Colossal Cave, a large cave system, and the Rincon Mountains District of Saguaro National Park, a top tourism spot within Arizona. Vail was originally a siding and water stop on the Southern Pacific Railroad.