Planet (The Savages)

This Earth-like planet was the home of the civilised Elders. They survived by draining energy from the primitive Savages who lived outside their city. The First Doctor put an end to this practice. His companion Steven Taylor remained behind to help unite the two peoples. (DW: The Savages)

A Sontaran scout ship crashed on the planet several years before Steven was transported to an alternative Death Zone on Gallifrey by Borusa. This experience taught him a Sontaran could be incapacitated by striking their probic vent. (BFA: The Five Companions)