1. Go to battlefield from inn
2. Talk to Colonel Thorodd
3. Choose about this fortress, and take the quest.
4. Go to these 3 cave and kill the boss in there
- Nidavelir South Trowulan Path (14, 15)
- Pirate Hideout Trowulan Harbour (21, 155)
- Reef Hinterlands (50, 52)
5. After you kill boss u will get the keys, collect all 3 keys and go back to Colonel Thorodd, He will exchange those 3 piece keys to Fortress Rune.
6. Now you can get inside the gruzar fortress.

Good luck!


-Habaek