Learners work in groups to design and build a tower out of balsa wood. As a motivator, they can compete to build a tower with the highest strength-to-weight ratio. Learners draw structurally sound 2D designs in the first part of the activity, then use those designs to construct the 3D structure. This activity is best used as a part of a larger lesson or after other building activities. Time for activity can be split over multiple meetings.