The Celestrial Dome is the exit point of Carthage. It has an interface that gives access to XANA's or Lyoko's data. When a Lyoko Warrior enters, Mantas usually come out of the outer sphere. While Aelita usually sifted through the data, the others had to deal with the Mantas 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 Carthage.