Atlanta is the the capital city of Georgia. It is the most populous city in the state, with an estimated population of 537,958 as of 2008 and is the urban core of one of the fastest-growing areas in the nation. The Georgia yellow pages will show you more about Atlanta. The Atlanta Combined Statistical Area is the 10th largest in the country, and the city itself is considered the unofficial central metropolis and capital of the American South. As a top business and transportation city, Atlanta is home to world headquarters of AT&T Mobility, The Coca-Cola Company and Delta Air Lines, as well as the corporate headquarters of Home Depot and UPS. More than 75 percent of the Fortune 1000 companies are located in the Atlanta area and the city has the 3rd largest concentration of Fortune 500 companies. Hartsfield-Jackson Atlanta International Airport, the world's busiest airport serves as the only major airport in Atlanta. Check out the business directory of Atlanta to find out more on these corporations. Development has been rapid and constant since 2006 including a construction and retail boom. The number of residential units has increased exponentially, and shopping areas have grown in numbers as well. There are many attractions in the area that draw over 400,000 visitors a year. The world's largest indoor aquarium, The Georgia Aquarium, opened here in 2005, and the new World of Coca-Cola opened adjacent to it two years later. Underground Atlanta, which consists of historic styled shopping and entertainment lies beneath the streets and Atlantic Station officially opened in 2005 as a new urban renewal project.