K'Nex City Builders building set - 325 pieces / 20 buildsUsing 325 classic style K'NEX pieces, become your own town planner with this kids building set. Encourage imagination and build 3D interactive toys from a skyscraper, a castle, a treehouse, an arch bridge and much more. This engineering set includes 20 different 3D building ideas and encourages the development of fine motor skills, dexterity, spatial awareness and problem solving using the colour coded rods and connectors specially designed to snap