I suspect it's just a spot to get some low to mid quality ores and herbs without being harassed by monsters. Oriana is just a means for a player to find it if they haven't already. Though I hope there is something more to it someday.
Oh, ok, thanks you guys. Then I have one more question. Is it possible somehow remove Acacia "curse"? Or she only needed to make the dark forest dangerous at night?
If by "curse" you mean what someone reported Orson saying about her, then I don't know if that's true, but likely a hallucination. I believe Acacia was added to make the higher quality herbs in the Deep Forest more difficult to harvest and as a bit of a surprise to spook people.
Oh, ok, when I was talking to her, she explained with drawings on the ground that there was a curse on her, so I had a question about it. Anyway thanks for the explanation, have a nice day!