An exemplary display of the latter is The Citadel. Over the course of three years, redditor [Shadowman39] pieced together this monstrous K’nex structure. With over 17 different paths(!), ...

Every year since 2013, students from area elementary and middle schools take part in the K'nex design challenge. It's a way to help students come up with an idea to make the world a little better.