The Atlanta BeltLine is a former railway corridor around the core of Atlanta which is being developed in stages as a multi-use trail. Right now, the Eastside and Westside trail (both easy, paved walkways) are open. Both have street art to enjoy along the way. Eastside is more developed. If it's your first visit, I'd recommend wearing tennis shoes and walking the easy 1.5 mile walk between Krog Street Market and Ponce City Market (see below). Along the way there are restaurants, New Realm Brewery and a cute French-style Brasserie called Bazati with a rooftop bar. Another wildly popular spot on sunny days is Ladybird Grove and Mess Hall.
The Westside trail is much quieter, as they're just beginning to add businesses. Parking there is free, and there are some great spots to eat and drink. Drinking spots include-- Best End Brewing, Monday Night Brewing: Garage, Wild Heaven, ASW Distillery, Hop City wine and beer shop, and Cultured South (a kombucha distillery.) Boxcar, the restaurant above Hop City, serves some truly delicious food.
Ponce City Market is a mixed-use development located in a former Sears catalogue facility (for my Memphis folks, think a Crosstown with more businesses!) It's a must-see with a large food hall, national shops and boutiques, along with a killer rooftop. Skyline Park has putt-putt, a giant slide, carnival games, and a restaurant. It does require buying a ticket to go up, unless you have a reservation at the rooftop restaurant.
Do you plan to pack all of your tourist attractions into one visit? You can buy a City Pass to visit all of the below locations for one discounted price. The pass is valid for 9 days, but you can certainly pack them into 1-3. Only recommended if you really want to do 3+ of the 5 locations! - Georgia Aquarium - World of Coca-Cola - CNN Studio Tours - Zoo Atlanta OR National Center for Civil and Human Rights - Fernbank Museum of Natural History OR College Football Hall of Fame If you want the day to stay walkable, I recommend opting for the Civil Rights Museum and the College Football Hall of Fame (then the whole route between the 5 is an under 7 minute walk)