Orlando is a major city in the central region of the U.S. state of Florida. It is the county seat of Orange County and the center of the Greater Orlando metropolitan region. Originally the center of a major citrus growing region, Orlando is a city now heavily urbanized with various industries. The area is a major tourist destination and is the home of Universal Orlando Resort, and SeaWorld Orlando. Lake Buena Vista, Florida, located 21 miles southwest of downtown Orlando, is the home of Walt Disney World. These attractions form the backbone of Orlando's tourism industry, making the city the third most visited American city. Orlando is also home to the University of Central Florida, the largest university campus by student enrollment in the state of Florida and among the largest in the United States.