Panoramic views of the Atlanta city skyline can be enjoyed from the 19-story Galleria 400 business center, centrally located in Northwest Atlanta about 20 minutes from Hartsfield-Jackson Atlanta International Airport. The complex boasts award-winning gardens and a lush landscape park with water fountains and a five-story carillon bell tower. Tenants include national companies specializing in real estate, insurance, and finance. Cobb County, which is significant historically for its many Civil War battle sites, has had a Triple-A credit rating since 1997. Cobb County is home to more than 350 international firms. Most employment is in the service industry with retail and manufacturing close behind. The county's largest single employer is The Home Depot. Dobbins Air Reserve Base is nearby, as is the Cobb Galleria Center, with 144,000sq ft of exhibit and function space. The business center has free underground parking and the Cobb County Transit System is easily accessible.