The Illusionary Maze is a three-dimensional representation of M. C. Escher's Relativity which was used as a set in Labyrinth (the Escher estate was given acknowledgment in the credits for the film). As one of Sarah's last challenges within the Labyrinth, she runs throughout this maze trying to catch up to her little brother so she can take him home. The law of gravity and that of physics do not apply here. At one moment, little Toby might be crawling across the ceiling, in the next he might be catching a crystal bouncing up a flight of steps.
In the book Jim Henson: The Works, Jerry Juhl comments on how Jim Henson would get so enthusiastically preoccupied with his work, that certain ideas of his - such as the Escher inspired set - would become submerged for a while:
“I was in London in 1985 while Jim was shooting Labyrinth. I walked out onto this giant soundstage and there was this huge set - the M. C. Escher maze used at the climax of the movie. Jim came down from a ladder and I reminded him that we had talked about using an Escher maze in a proposal we had worked on twenty years earlier. He had absolutely no recollection of it. We actually went back and found the treatment, but he still didn't remember. That was so typical of Jim. He always said that he didn't have a good memory, but in fact he always hung on to useful ideas until they were needed.”