The Forest Sector (referred to as the Forest Region in Season 1) is a Sector of Lyoko. It is mostly a complex series of paths intertwining between thousands of trees, but raised high above the Digital Sea. Large open areas are not as common as those in the Desert and Ice Sectors. It also has a lot of hollow tree trunks which connects areas of the Forest Sector and has often saved the lives of the Lyoko Warriors.
Despite the fact that paths are narrow in this sector, X.A.N.A. often sends its largest monsters, such as Megatanks and Krabs, to attack Lyoko Warriors when they are trying to deactivate a tower there. It is also the only sector in which X.A.N.A. directly attacked a tower, once in Code: Earth and again in Contact.
The appearance of this sector changed noticeably between Seasons 1 and 2. In season 1, the lighting was much darker and the color tinted much more towards brown. In Season 2, the lighting and terrain were lightened, with the colors leaning more towards a neon green. These changes remained present for the reset of the series.
In Marabounta, Jeremie materialized a monster with the same name into this sector with the intention of having it attack and destroy X.A.N.A.'s monsters. However, it also attacked Aelita, and the other Lyoko Warriors after they attack it to defend her.
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.
The Forest Sector is numbered as Sector 3, as it is the opposite of Sector 1.
- X.A.N.A. Awakens, Part 1 (debut)
- Seeing is Believing
- Holiday in the Fog
- Cruel Dilemma
- The Girl of the Dreams
- Swarming Attack
- Just in Time
- Code: Earth
- Uncharted Territory
- Saint Valentine's Day
- Missing Link
- Tip-Top Shape
- Is Anybody Out There?
- The Forest Sector contained the tower Aelita hid in while the Supercomputer was off for several years.
- The Forest Sector was the only Sector where X.A.N.A. attacked a tower, both in seasons 1 and 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 X.A.N.A. Aelita.
- Lyoko Minus One was the only season 3 episode that the Forest Sector appeared in, not counting the flashbacks Aelita had in her own self-titled episode.
- This was the first sector Aelita was virtualized into.
- This was the first sector Odd and Ulrich were virtualized into in X.A.N.A. Awakens, Part 1.
- This was the first sector with a Replika shown.
- This was the first sector Sector Five was accessed from.
- This was the first sector where Scyphozoa attacked someone other than Aelita; Yumi.
- This was the first sector where someone fell into the Digital Sea; Yumi.
- The Forest Sector was the first sector Franz Hopper was seen in.
- This was the first sector to have a tower activated by Franz Hopper.
- This was the first and only sector that the Marabounta was shown in.
- Like the Ice Sector, the forest has simulated water which one could possibly swim in. Yumi once skimmed on it with the Overwing in "Temptation".
|Ice Sector | Desert Sector | Forest Sector | Mountain Sector | Carthage|
|Ice Replika | Desert Replika | Forest Replika | Mountain Replika | Volcano Replika | Carthage Replika|
|Other Virtual Worlds|
|Digital Sea | Cortex | Virtual Limbo | Simulation Bubble|
|Dormitory Building | Administrative Building | Cafeteria | Gym | Track | Park | Hermitage | Science Building | Playground | Garden Shed | Infirmary | Boiler Room|
|Union Base | New Mexico Research Facility | Space Station | Jungle Research Facility|
|Renault Auto Factory|
|Factory Floor | Factory Lift | Lab | Scanner Room | Supercomputer Room | Assembly Room | Security Center|
|Kadic Academy | The Sewer | The Factory | Ishiyama residence | The Pool|