Wind-up toys are mechanical toys powered by a coiled spring. When you turn a key or a lever, the spring tightens, storing energy. Once released, the spring unwinds, causing the toy to move, spin, or perform specific actions. These toys come in various shapes, including animals, cars, and robots. Popular since the late 19th century, wind-up toys are often made of metal or plastic. They are simple yet fascinating, showcasing basic principles of mechanics. Many collectors enjoy vintage wind-up toys, which can be found in antique shops or at toy fairs. They serve as a nostalgic reminder of childhood play.