Sarn (planet)

Sarn is a volcanic planet, which at one point was a colony of Trion. The Trions mainly used Sarn for its regenerating Numismaton Flame, over time the Trions neglected Sarn and began using it as a dumping ground for political prisoners.

The people of Sarn descended from what was a relatively high technology society into tribalism and superstition, they worshiped Logar God of the Fire Mountain. They sacrificed unbelievers in fire.

When Turlough and the Doctor went to Sarn Turlough sent a distress call to Trion, requesting assistance for the people of Sarn who were threatened by a volcanic eruption. (DW: Planet of Fire)