Isle of the Doomed is another island besides the Isle of the Lost and keeps the object of some of the weapons of each villain.
This was originally Maleficent's home, The Forbidden Fortress or Mountain. When Carlos De Vil accidentally broke the barrier of the isle, he brought back Diablo to life. When Mal, Evie,Jay, and Carlos enter the fortress, it is protected by thorns and poisonous spiders.Then some of the old properties of their parents come to life, they are going to have to faced them on a challenge. Many traps were reactivated and proved a hindrance to Mal's attempt to retrieve her mother's staff; this includes the Cave of Wonders, a magic mirror, and gargoyle sentries. Many of the goblins that served Maleficent still remain on the isle, but have devolved into cannibals after making the poor choice of waiting all these years for Maleficent to return.
Exactly in the middle, the throne room is located, a round circular room with two spiral staircases leading to the balcony where the throne stood. There is also a staircase leading towards the Dungeons.
In one of the highest towers Maleficent's bedroom is located.
On the ground floor there is a gallery located and the goblins quarters. There are also rooms for the Magic Mirror and the Cave of Wonders.
- Maleficent's Goblins
- Diablo (formerly)
- Although the forbidden mountains appear to be on this isle, in Descendants in the prologue, on the map, it is shown to be in Auradon, next to the Bald Mountain.