Educational toy made in plastic versions. In the mid-1950s, more explicitly engineering-themed construction toys appeared, including plastic girders, columns, and panels that could be assembled into a model curtain wall skyscraper. Later, this Girder and Panel structural system was extended to a Hydro-Dynamic setup by adding pipes, valves, tanks, nozzles, and pumps to allow construction of model plumbing, HVAC, and chemical engineering systems like a simulated distillation column. Other extensions of the system supported suburban-style housing developments (Build-A-Home), or monorail transportation systems (Skyrail). The building toy Lego was originally developed by Ole Kirk Christiansen in Billund, Denmark, in the 1930s. The name
Lego Duplo key antagonists in the sequel, "". It was the sponsor of the British children's television series "Tots TV" on CITV. Lego Duplo Duplo (trademarked as DUPLO) is a product range of the construction toy Lego, designed for children aged 1½ to 5 years old. Duplo bricks are twice the length, height and width of traditional Lego bricks, making them easier to handle and less likely to be swallowed by younger children. Despite their size, they are still compatible with traditional Lego bricks. Initially launched in 1969, the Duplo range has gone on to include sets with figures, cars, houses and