The Ice Sector
The Ice Sector is one of four surface sectors of Lyoko. It is sometimes referred to as the Polar Region/Glacier Region in Season 1 because it is covered in ice, or Sector 1 (as referred to in Mister Pück and Saint Valentine's Day). Like the Desert and Mountain Sectors, it also has virtual weather, as pointed out by Odd in The Girl of the Dreams, as he told Jeremie that Aelita might have been trapped in a snowstorm.
​
The Ice Sector is made up of two major parts. The first part is the surface, composed of glaciers connected by narrow paths and large lakes of icy water. Monsters cannot swim, so the icy waters will destroy them if they fall into it. Most of the towers are based on the surface. The second part of the sector is below the surface; tunnels connect the two areas. The Lyoko Warriors often have to surf down these tunnels to get to an activated tower.
​
Due to its difficult range of reachable locations, X.A.N.A. placed his simulation bubbles in this sector in the episodes Ghost Channel and Distant Memory.
​
In Sabotage, X.A.N.A. activated a tower in the Ice Sector that was too well-guarded for the heroes to reach, and they were running out of time as the Supercomputer was at the edge of being destroyed, so Aelita deleted the Ice Sector at her own will, giving the Supercomuter the energy needed for a reboot and destroying the activated tower in the process.
The Ice Sector made its first reappearance in Crash Course, as it was recreated along with all the other outer sectors between the episodes William Returns and Double Take.
​
In Season 1, this Sector was used to have a strange light source that was always lighting and shadowing the Lyoko Warriors' faces. It is most likely that it was Sector Five's shining outer shell, but it is unknown why the light was taken away in Season 2.