Tigus

Tigus was an uninhabited planet with high levels of volcanic activity due to it being quite a new planet; the Doctor referred to it as 'a young planet, cooling down'. The Monk attempted to strand the First Doctor and his companions there, but the Doctor figured out how to escape in a few minutes. (DW: The Daleks' Master Plan)

The planet was protected under the Galactic Heritage. (EDA: The Tomorrow Windows)