M. C. Escher
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Maurits C. Escher was an artist famous for creating confusing engravings. (AUDIO: The Forever Trap)
Laura Corbett said that the Land of Fiction was "very M. C. Escher". (AUDIO: The Crooked Man)
The Tenth Doctor compared the Edifice to "the steps that go up and up and join up". (AUDIO: The Forever Trap)
The Eleventh Doctor, while trapped in the Bank of England, jokingly remarked that it was designed by Escher. (GAME: The Eternity Clock)