I know what you're thinking, but really, check out the Per-Level Hunting Guide (link in sig) ... and I say that as a personal opinion.
I like relaxing spots too, and I leveled a Druid to 60, so if you click the Druid filter on the Per-Level guide you're going to find lots of such spots. Mostly they'll be "relaxing" in the sense that you'll charm fight two mobs (or maybe do two such fights in a row, depending), or do a quad of mobs ... and then
relax and meditate
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If you want relaxing in the "root/rot one mob while being completely safe the whole time" sense ... I think you'll find that's mind-numbing slow compared to charming/quadding (or even grouping), and as a result it will be hard to find people who've done it.
But all that doesn't start until you really get into the class and can start charming, which I remember being a "late teens in the Karanas" deal (although I guess some people charm mammoth calves in Everfrost earlier?) The point is, at 10 you're still kinda in Wizard mode, so the class plays differently, and you just want to do whatever, wherever, to get to "real Druid" levels.
Finally, to answer the "really fun" part: alligators in Cazic Thule. I stayed in that zone for like ten levels and wrote two mini-guides for the "
alligator pit" and "
alligator alley" because I loved them so much. It's
not relaxing, but it's great/fast XP, keeps you on your toes, and really teaches you how to charm fight well, use Harmony to pull well, etc.