This 123-piece STEM building set's easy-to-handle pieces support multiple build-it-yourself castle designs - kids can add a bridge, stack up a tall turret, or design an open courtyard as they bring their creations to life! The Engineering & Design: Castle building set also comes with a set of 10 double-sided Activity Cards filled with interactive challenges designed to boost critical thinking, problem-solving, and early engineering skills - can you lower the drawbridge, build a working catapult, or trigger the surprise trapdoor? In addition to building and rebuilding the castles of their dreams, kids can also go on imaginative adventures with the help of this engineering set's two included knight figures and a trusty horse that's ready to set off on any fantasy quest your kids can dream up.