If you think an ordinary Rubiks cube is hard to conquer then I wouldn't recommend the massive one that is the Ars Electronic Building.
Located in Linz, Austria the Ars Electronic Building is the world's largest playable Rubiks cube. With color-changing illuminated facade controlled by a 3D-printed device just about anyone brave enough can try their hand at this challenging and massive puzzle. Designer Javier Lloret uses Bluetooth to connect the smaller cubes software program that converts the information into color and light.
With only being able to see two sides of the building at a time due to its immense size, I can guarantee this version of the puzzle is no easier than the original.