Have you ever heard of the Mbius band? It is a complex surface whose front and back are indistinguishable. In this puzzle, obstacles are placed on the surface and block the path, as in a labyrinth. When you advance, the front becomes the rear and vice versa, which leaves you perplexed. Created by Oskar Van Deventter from the Netherlands. Difficulty : Difficult. Please note, the heads are provided without resolution instructions. However, many videos can be found on the internet and YouTube explaining how to resolve them.