|First appearance||Production: Holiday in the Fog Chronological: X.A.N.A. Awakens|
|Also known as||sector 3|
|Terrain features||A network of pathways and small platforms filling a mass of tree trunks.|
The Forest Sector is a sector of Lyoko. It is mostly a complex series of paths intertwining between thousands of trees. Large open areas are not as common as those in the Desert and Ice Sector. It also has a lot of hollow tree trunks which connects areas of the Forest Sector and has often saved the lives of our Heroes.
Despite the fact that paths are narrow in this sector, X.A.N.A. often sends his largest monsters, such as Megatanks and krabs, to attack our heroes when they are trying to deactivate a Tower there. It is also the only sector in which X.A.N.A. directly attacked, once in Code: Earth and again in Contact.
The appearance of the sector changed noticeably from Season 1 to Season 2. In Season 2, the sector had a "morning look" (the lighting) and the paths were more detailed. In Season 1, the path was a dull green and there were far less trees. The lighting was also taken out.
The Forest Sector was recreated between the episodes William Returns and Double Take by Jeremie and Aelita. It made its first reappearance in Opening Act and the new forest appears to have new areas added on such as the forest arena. In Marabounta, Jeremie materialized a monster called the Marabounta into this sector with the intention of having it attack and destroy X.A.N.A.'s monsters. However, it also attacks Aelita, and the other Lyoko Warriors after they attack it to defend her.
The forest sector is numbered as Sector 3, as it is opposite Sector 1.
- The Forest Sector was lost between seasons 4 and 5. It's unkown if Jeremy will recreate it.
- The Forest Sector was only shown in one episode of season three: "Lyoko Minus One."
- The Forest Sector contained the tower Aelita hid in while the Supercomputer was off for several years.
- The Forest Sector was the only Lyoko sector where X.A.N.A. attacked a tower, both in season 1 and in season 2; not counting replikas.
- The Forest Sector was the first sector to appear chronologically.
- The Forest Sector was the first sector deleted, in "Lyoko Minus One," by Aelita, possesed by Xana.
- The Forest Sector was the first sector Aelita was virtualized into.
- The Forest Sector was the first sector Aelita was materialized from.
- The Forest Sector was the first sector was the first sector with a shown replika.
- The Forest Sector was the first sector Carthage was accessed from.
- The Forest Sector was the first sector the Scyphozoa attacked anyone other than Aelita. "Yumi"
- The Forest Sector was the first sector that someone fell into the Digital Sea from. "Yumi"
- The Forest Sector was the first sector where a tower was shown activated by Franz Hopper.
- The Forest Sector was the first and only sector that the Marabounta was shown.