The Celestial Dome is the exit point of Sector Five. It has an interface that gives access to X.A.N.A.'s or Lyoko's data. When a Lyoko Warrior enters, Mantas usually "hatch" out of the outer sphere. While Aelita usually sifted through the data, the others had to deal with the Mantas which would appear until Aelita was done. After that, Jeremie usually programmed their Vehicles, and they went through a tunnel leading to another sector. As of Season 4, the tunnels led out of the craggy outer shell of Sector Five.
After the destruction of Lyoko, the fully recreated Sector Five Interface was not shown again until Fight to the Finish when Aelita used it to launch Jeremie's multi-agent program to exterminate X.A.N.A. once and for all. It later appeared in Virus when Aelita was testing a program on the Core of Lyoko.
- It is where the core zone can be accessed, where the very Heart of Lyoko itself resides in the very center.
- Vital data information can be accessible as well through an interface.