You know that feeling, right? The rush of conquering a tough raid, or the pure joy of finally beating that nightmarish level.

Liberty Puzzles has been making handmade wooden puzzles in Boulder for nearly 20 years, but the company's story started ...

Not only do his varied puzzle box designs show his math background, but they are all made entirely of wood. There are no nails ... two things stood out to us as being of particular interest.