Castle Castles were large fortified buildings , often used as the residence of royalty or nobility . On Earth , castles were usually located in Europe . Castles on Earth . Castles located in Great Britain included Windsor Castle in England , ( TV : " Silver Nemesis " ) Balmoral Castle and Forgill Castle in Scotland ( TV : " Tooth and Claw " , " Terror of the Zygons " ) , and Cardiff Castle in Wales . ( TV : " Everything Changes " ) Wessex Castle was taken over by Irongron ; it was destroyed when Linx ' s spaceship exploded . ( TV : " The Time Warrior " ) A castle owned by Lord Geoffrey de Beauvain was taken over by his brother Lord Waldean de Beauvain . ( COMIC : " The Magician " ) The Sheriff of Nottingham ' s castle was actually a spaceship that had assumed the likeness to disguise itself . ( TV : " Robot of Sherwood " ) Professor Logan lived in a castle , his ancestral home . ( COMIC : " Doctor Who and the Rocks from Venus " ) Vicki lived near a castle when she was very young . ( TV : " The Chase " ) Other Earth castles included Drachensberg ( PROSE : " " ) and Colditz Castle , ( AUDIO : " Colditz " ) both in Germany . Some castles were converted into other uses . One became Stangmoor Prison , ( TV : " The Mind of Evil " ) while another was used as the Pharos Institute ' s headquarters . ( TV : " The Lost Boy " ) One castle in Scotland was used by the Quark s as their base ; it was destroyed by the Second Doctor and Jamie McCrimmon . ( COMIC : " Invasion of the Quarks " ) When the Twelfth Doctor decided to meditate before his meeting with an old friend , he obtained a castle in medieval times , ( TV : " The Doctor ' s Meditation " ) in which he later threw a party . ( TV : " The Magician ' s Apprentice " ) The Celestial Toymaker created a castle in the sky above Stockbridge which appeared to be made of LEGO . ( COMIC : " Endgame " ) Castles on other planets . The rulers of Peladon based themselves in the Citadel of Peladon on the side of Mount Megeshra . ( TV : " The Curse of Peladon " , " The Monster of Peladon " ) On Tara , Castle Gracht was the residence of Count Grendel of Gracht . ( TV : " The Androids of Tara " ) On the " vampire planet " , the spacecraft " Hydrax " was converted into a castle by the Three Who Rule . ( TV : " State of Decay " ) Castle Extremis was used to host the signing of the peace treaty between the Anthium and the Zerugma . ( PROSE : " Martha in the Mirror " ) The residents of one unnamed planet , who were threatened by Mirrorling s , put all their mirror s in a castle to protect themselves . ( COMIC : " Mirror Image " ) Zentor lived in a castle on the Haunted Planet . ( COMIC : " The Haunted Planet " ) The sons of Grekk lived in a castle on an unnamed planet . ( PROSE : " The Sons of Grekk " ) A castle called the Space Citadel was defended by monsters . ( GAME : " The First Adventure " ) The monarch of Industry ruled from a castle . ( AUDIO : " Time Works " ) On Hedgewick ' s World of Wonders , there was a working castle known as Natty Longshoe ' s Comical Castle . ( TV : " Nightmare in Silver " ) A castle on Safeplace was actually one of the segments of the Key to Time . ( AUDIO : " The Judgement of Isskar " ) Castles in other dimensions . The Gateway was a castle used by the Tharil s as the centre of their empire . ( TV : " Warriors ' Gate " ) Morgaine lived in a castle in her home dimension . ( TV : " Battlefield " ) The Pied Piper lived in a castle when he took the children of Hamelin to his own realm . ( COMIC : " Challenge of the Piper " ) The Sixth Doctor and Frobisher confronted Astrolabus in a castle in his realm . ( COMIC : " Once Upon a Time Lord " ) Eugene Tacitus ' prison took the form of a medieval castle . ( AUDIO : " The Holy Terror " ) The Twelfth Doctor spent four and a half billion years ( TV : " Hell Bent " ) in a castle in his confession dial punching his way through an azbantium wall . ( TV : " Heaven Sent " )