When you are done that and around level 25, Stone's flying fortress would bring you up another couple levels (I entered at level 25 or 26 and got to 29 just at the end), and Raze's would add another couple levels (I got to 31 near the end); both entrance teleporters are in the mountains near the harbor. After that I cleared out a few imps and goblins to the far east I should have done sooner, and Kali's fortress (to the far south east in the fjords) brought me to level 33.
