Befallen

[Zallar]

I leveled my mage in Befallen from 8 or 9 to 15 or 16 I think it was. Grouped on the 2nd floor or just solo'd it. There are only a few rooms you can't solo on the 2nd floor. Get to know the zone, the ZEM is the bomb and as long as you're willing to do a /who all 8 15 ecommons and send some tells, you can form a group in there really easy.

Don't bother with CB, you're a mage, own the dungeon.