Tersurus

Tersurus was a planet with singing stones and clone banks. (PROSE: All-Consuming Fire) It was mentioned as being in the "Outer Planets" in the Matrix. (AUDIO: Neverland)

History
In the Old Time, the Other sent Susan Foreman to Tersurus during the Great Schism so that she would be safe from the civil war erupting on Gallifrey. (PROSE: Lungbarrow)

Following a ploy with the Daleks on 22nd century Earth, travelled with Susan Foreman in his his TARDIS to Tersurus, where she believed she killed him. During the encounter, his TARDIS sent a signal to Gallifrey which brought Chancellor Goth to Tersurus. Thee he found. (PROSE: Legacy of the Daleks, TV: The Deadly Assassin)

The Time Lords had an outpost on Tersurus. infiltrated their base in order to gain forbidden knowledge on the Dimensioneers. (AUDIO: UNIT: Dominion)

After his TARDIS was damaged by a vortex parasite, the Eighth Doctor patched it up on Tersurus. (COMIC: A Life of Matter and Death)

In 6211, a Sontaran stealth raid destroyed Tersurus with an earthshock bomb which they had obtained from the Cybermen. (PROSE: The Crystal Bucephalus)

The Curse of Fatal Death
Tersurus is a setting in the Comic Relief special mini The Curse of Fatal Death, which this wiki does not consider to be a valid source. In the special, a Time Lord known as the Ninth Doctor accompanied by his companion, Emma, meets with the Master on the planet to tell him the news that he has plans to marry her and retire.

The special also gives details on the natives of Tesurus, the Tersurons. The Doctor explains to Emma that the Tersurons were a kindly, peace-loving race, but shunned and abhorred due to their communicating solely through precisely modulated farting. They destroyed themselves after discovering fire.