One of the best parts about summer is taking your favorite playlists (and a good set of mini speakers) outside. But you know what’s even better? Enjoying that music live during an awesome outdoor fest. No, this isn't a very early notice to get your tickets for Coachella next year — there's a way-cool festival happening right here in our own backyard next month.We're talking about the inaugural Firefly Festival, which goes down in Dover, DE, the weekend of July 20. This brand-new Mid Atlantic musical experience hosts an impressive roster of acts, and is spread out over three days — that's right, three days. Headliners include The Killers, The Black Keys, and Jack White, plus tons of other favorites like Death Cab for Cutie, Cold War Kids, Lupe Fiasco, Cults, and many, many more. There’s no question about whether or not you should go — you should. Once you score the $218 ticket to get you into three days' worth of shows, the only thing that'll be up in the air is what to pack. (Well, that, and the festival's hot air balloon rides.) Click through to see our list of must-haves for your first trip to Firefly.