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 Friends Lego Friends Lego Friends (stylized LEGO Friends) is a product range of the Lego construction toys designed primarily for girls. Introduced in 2012, the theme introduced the "mini-doll" figures, which are about the same size as the traditional minifigures but are more detailed and realistic. The sets include pieces in pink and purple color schemes and depict scenes from suburban life set in the fictional town of Heartlake City. The Friends product range replaced Lego's previous female-oriented theme Lego Belville, which had been in production since 1994, and featured dolls that were much larger than both the mini-dolls and minifigures.