Traken was the homeworld of the Trakenites, a race of pacifists, and the capitol of the Traken Union. Its many plants required much care.

The planet was in the system Metulla Orionsis and was watched over by the Keeper of Traken. It was said that there was so much good in the air that evil would just shrivel up and die.

The Doctor's companion, Nyssa, was a native of Traken. (DW: The Keeper of Traken)

The Doctor took Nyssa to Traken in the primeval age to cure her of an illness. (BFA: Primeval) In 1981, Traken and Metulla Orionsis were destroyed by a wave of entropy. (DW: Logopolis)