Land of Fiction
The Land of Fiction is a pocket universe inhabited by characters from various works of fiction, mythology and folklore. (DW: The Mind Robber)
Possible origins
One account revealed that the Gods of Ragnarok created to entertain the Gods of Ragnarok. (DW: Conundrum).
Adventures of the Doctor in the Land
The Doctor first visited the Land of Fiction shortly after defeating the Dominators on Dulkis. To escape a volcanic eruption there((DW: The Dominators), the Doctor flipped an emergency switch in the TARDIS to escape the lava. Consequently, the TARDIS materialized in the White Void with White Robots and force that invaded the minds of the travelers. They manage to return to the safety of the TARDIS which appeared in another, dark void. The TARDIS exploded, leaving Zoe and Jamie clinging to the TARDIS console, spinning in space and the Doctor floating nearby, seemingly dead.
After a dream-like transition, the travelers found themselves waking in a world called the Land of Fiction, without the TARDIS. The White Robots re-appeared, this time as Clockwork Soldiers. In the Land, mythical and fictional characters such as Lemuel Gulliver and unicorns (some based on actual beings) had a physical existence, as did puzzles, riddles and puns. (DW: The Mind Robber)
Bernice Summerfield, on a quest for behest of the White Guardian encountered the travelers as they wandered a maze. (DW:Time & Time Again)
They found this realm to be under the control of an unseen presence known as the Master of the Land who attempted to turn Jamie and Zoe into fictional characters and to trick the Doctor into assuming the place and rule the Land. A futuristic computer, the Master Brain had forced the Master of the Land into its slave.
The Master of the Land was in fact a benign old man, a writer of boys' fiction from Earth in the year 1926 who had also been trapped in this universe and taken over by the Master Brain. Zoe and Jamie were able to overload the Master Brain's systems, destroying it and freeing the old man from its control. Once the Master Brain was destroyed, vanished, while the TARDIS re-assembled around them (DW: The Mind Robber) and they found themselves returned to the normal universe (DW:The Invasion).
::Some ambiguity had earlier existed as to whether the traveler's had simply imagined the Land of Fiction. However, later stories more or less confirmed the Land of Fiction as "real",::
As part of his elaborate scheme to gain revenge on the Doctor, the Monk reactivated the Land and installed a mentally unstable boy from 1993 Earth, named Jason, as its new Master. Jason constructed a town called Arandale, inhabited by various fictional characters such as the White Knight and Dr. Nemesis. He then trapped the Doctor, Ace, and Benny in this scenario. By tricking Jason into introducing highly disruptive McAllerson's Radiation into the Land, the Doctor was able to escape, and at his request the Time Lords placed beacons around the Land to warn away other travellers in space and time who might become trapped there. (DW: Conundrum)
The actions of Kadiatu Lethbridge-Stewart to enable herself to time travel (DW:Set Piece) created a space-time anomaly which allowed energy from the Land of Fiction to bleed into the real universe. This created the Miracle, an energy source which for a time sustained the dying planet Detrios. It also re-activated Jason, who sought to gain revenge on the Doctor by creating a fictional version of the Doctor, Dr. Who. Jason then employed Dr. Who in a plot to assassinate Queen Elizabeth II. Although the Queen was killed by Dr. Who, Jason's distaste for bloodshed moved him to use his powers to restore her to life. Jason then assisted the real Doctor in sealing off the anomaly, after which the Doctor wiped Jason's memory and returned him to Earth (DW: Head Games).
Other adventures
The Master visited the Land of Fiction and handily destroyed a council of 19th century book villains who resided there (Character Assasin).