Goroma
One of the islands in the Forbidden Islands archipelago where followers of the Voodoo Cult have their headquarters. It is a really dangerous island due to the monsters found there, so without knowledge of it or a high level, it is not recommended to venture into the region. Even pirates are said to avoid it. It is also inhabited by an NPC named Atrad, who will help you complete the Assassin Outfits Quest.
When you sail from Liberty Bay to Thais, there's a chance you'll hit a storm and get to this very island.
Monsters found on the island: Island Troll, Crab, Cobra, Scorpion, Pirate Skeleton, Fire Devil, Ghost, Witch, Stone Golem, Blood Crab, Fire Elemental, Pirate Ghost, Elder Bonelord, Acolyte of the Cult, Efreet, Adept of the Cult, Enlightened of the Cult, Dragon, Dragon Lord, Demon, And during the attack: Morgaroth