Design and engineer the tree house of your dreams with this one-of-a-kind building set. Use the five included activity cards to complete engineering challenges. Build railings, platforms, trees and then use your problem solving skills to re-engineer your design. Kids will love building their tree house, and parents will love that they?re actually building critical thinking and STEM skills. A unique way to challenge children and help them develop logic and problem solving skills. 52 building pieces. For ages 5 and up.