This dungeon is the hidden location of Olaf Hradson's grandfather's last treasure, and is discovered during Olaf's Quest. It is populated by Skeleton Fremenniks of various levels, and is the only area Brine rats, which drop the Brine sabre (a sword with an underwater special attack), can be found.

Brine rat (Level 70) Giant bat (Level 27) Rock crab (Level 13) Skeleton fremennik (Level 40) Skeleton fremennik (Level 50) Skeleton fremennik (Level 60)