I don't know if anyone's already posted this but in Maxos temple in the mirror room trial if you go straight in and go into the alcove straight ahead where the two chairs are and look to the right there is a barrel that weather full or empty if you look in it then out again, enemies keep spawning every time you do! Don't ever break it and you can level up at least 3 maybe four times its very time consuming but easy. You keep getting less Xp every time you level up so it takes longer.
I'm now at High Hall at level 26.
