Long before Rubik's cube, there was the Chinese puzzle ball: a set of intricately carved, concentric spheres usually up to 7 layers deep.
The "puzzle" part of the name is both for the fact that it's a game that people can solve (by aligning the holes of the spheres) and by the mind-bending question of how they are made in the first place.
So how exactly are these puzzle balls made? Oddity Central has the answer: Link (photo: KW Monster)