A puzzle origami, by Piet Hein. It’s a fun toy to kill time, I spent about 10 minutes completing the puzzle after I finished making the individual pieces. It’s like the paper equivalent of Rubik’s Cube.
It’s composed of 7 different pieces made out of strips that look like those in Tetris (but in 3D). You can also make 6 pieces which would make it easier to assemble, here’s a Soma cube with 6 modules made with Sonobe modules.
If you really like this model and you have trouble with strip origami you can make it out of Sonobe units which are very easy, but I doubt it will be as sturdy.
Paper to use
An easy to fold/tuck paper, I used old school notes and cut the strips 2cm wide.