Celebrate Earth Day right with good booze, food, music and art at the SWEETWATER 420 FEST in Candler Park Sat., APRIL 19. Outformation headlines on Saturday followed by Grace Potter and the Nocturnals on Sunday. Other local and regional bands such as the Rockin Pontoons, Entropy and Kingrat will also appear as part of this huge outdoor festival. In addition to great local music, the weekend will include an extended environmental expo where party-goers can learn about Mother Nature's problems and how to fix them. With a MARTA station within walking distance, you can even get a head start toward reducing your carbon footprint. Mother Nature and your designated driver will thank you. Through April 20. Free. Sat., noon-11 p.m.; Sun., 12:30-10 p.m. 1500 McLendon Ave. www.sweetwater420fest.com.