Planet (The Arboreals)

An Earth-like planet that was in a state of perfectly tuned balance. It was 483 light-years away from Earth Central. Earth once attempted to colonise the planet, but the colonists, influenced by the effects of the planet, decided to revert to a simpler way of life, informing Earth central not to bother with the colonisation attempt. The First Doctor and Susan visited the planet, and the Doctor theorised that the world had its own ways to survive, despite Susan's concern at the threat it might encounter from Earth Central. (PROSE: The Arboreals)