Level 30 is way too much for the palace. And boring to boot because you don't have a party.
Palace: I was level 10 and did good
Lhusu Mines: Got my but kicked at level 11, got by easily at level 21. Good place to level up
Ogir-Yensa Sandsea: Went by easily at level 22. Good place to level up
The Tombo of RaithWall: Got my butt kicked at level 26