5 years & up. Your little engineers will love designing and creating their own skyscrapers, cranes, bridges and more with this City Engineering® & Design Set by Learning Resources. Use the activity cards to complete design challenges or let your imagination run wild and create your own city. The perfect set to encourage early STEM learning. Platform measures 4.25" x 4.25". Included: 89 Easy-to-assemble pieces: Gears, building pieces,2 figures, a truck, a construction cone and more, and Activity cards.