The Phantom Zone is a prison dimension used by Kryptonians. It was originally discovered by Jor-El and used by the Kryptonian Council as a humane prison. Although the zone is a barren wasteland, people trapped in the zone can never get old or die, and can see outside of the zone and watch the events of the outside world. The zone first appeared in the silver-age comics of the 1960s. It was used frequently in the before the continuity was rebooted in the 1980s, and has appeared occasionally since. It has also appeared in other adaptations of Superman.