A maze is a tour puzzle in the form of a complex branching passage through which the solver must find a route. In everyday speech, both maze and labyrinth denote a complex and confusing series of pathways, but technically the maze is distinguished from the labyrinth, as the labyrinth has a single through-route with twists and turns but without branches, and is not designed to be as difficult to navigate. The pathways and walls in a maze or labyrinth are fixed (pre-determined) – puzzles where the walls and paths can change during the game are categorised as tour puzzles. The Cretan labyrinth is the oldest known maze.