Varos

Varos was a planet located in the constellation of Cetes. Humans used the planet as a prison colony until the rare Zeiton-7 was discovered there. The colonists were kept entertained by televised footage of various tortures and executions of the prisoners. The planet was really ruled by Sil, a Mentor who controlled the sales of Zetion-7.

The Doctor and Peri visited Varos in the late 23rd century when the TARDIS required Zetion-7. (DW: Vengeance on Varos)