- Main article: The Maze
The Walls refer to the boundaries of the Maze surrounding the Glade, which rise 200–300 feet high. In the book, some of the walls of the Maze move each night, forming parts of letters that produce the code to stop the Grievers; at the end of the book the Gladers used maps of the Maze overlaid on top of one another to find the letters. In the movie, the walls move to allow access to different sections of the maze every day, each of which has a number that when put together in order creates the code to stop the Maze and Grievers. It is built of gray stone and covered with thick ivy, but the Gladers were unable to climb the ivy to solve or exit the Maze. The walls close the entrances to the Glade each night, to protect the Gladers from the Grievers, but at the end of The Maze Runner (book and movie), the entrances remained open, even during the night, allowing the Grievers access to the Glade.