Xooberon is a fictional planet first seen in Series Two's Fountain of Youth.
It is the homeworld of Naboo the Shaman and Tony Harrison (revealed during the future sailors tour), ruled by a King with nice hair, and the setting for the legendary Desert of Nightmares which one must cross to reach the Fountain of Youth. The desert is inhabited by a race of blue men with a very short leader, and they act as guardians of the fountain.
To get from Earth to Xooberon a magical (battery-powered) amulet is needed, though there must be other ways of moving between the two for The Hitcher is also seen there - Although he could have just hitch-hiked on a space ship.