Pablo Picasso once said: "Youth has no age". So no matter your adult age, use these puzzles as much as possible.

This puzzle looks like a box-shaped skein with a hole in the center, but it's actually made up of two practically identical and twisted pieces: you have to try to separate them by sliding or rotating them. Although the pieces are square, they can be rotated in a surprising way and their movements can be particularly fascinating. The subject of this puzzle is the ring.
The creator is the Japanese Edi Nagata.