The Ghosts northeast of Anair Harbor are a pretty good place to grind at level 40. These ghosts are quite squishy and I'd recommend them to any class that doesn't have buffs. There is a Mage type of Ghost here that uses Dispell Blessing. This can get quite annoying as a Chanter since they take away all of my buffs.
I can see a Gladiator or Assassin type class eating this area alive. The ghosts here don't have much defense and low HP. You should be able to drop them pretty quickly without much downtime in between fights. Also if you have gathering at a decent level you will be able to gather the Moonstone here (280 skill) and Orichalcum (300 skill).
For the ghosts there is also a repeatable quest you are able to accept in Besfer Refugee Camp at level 40. This quest is called "[Coin] Ghosts of Anair Harbor". It requires you to kill 12 Spiritsoldiers, 8 Spiritmages and 11 Spiritarchers.
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