The Forbidden Islands are an archipelago of islands north-west of Vandura. The islands are comprised of (counter-clockwise from upper right) Goroma, Ramoa, Talahu, Malada and Kharos, and are fraught with danger and intrigue.
All of the Forbidden Islands are dry and nearly uninhabitable. Many dangerous Creatures thrive here, and some outlaws use these islands to avoid the long arm of Thaian law.
In order to get access to all of these islands you need to do The Shattered Isles Quest.