LEGO 40505 Building Systems is a tribute to the different building systems that are used to this day: Duplo, System and Technic. This set consists of three iconic micro-buildings, each focusing on a different building system. On the left you can see a combination of LEGO DUPLO 2700 and 2705 Train set, in the middle LEGO 810 Town Plan and on the right LEGO Technic 853 the Car Chassis. On the back of this set there are 19 micro builds of iconic LEGO sets. There is room for 20 micro builds, you can fill the empty space with your own build that you have good memories of. The micro builds consist of a complete timeline of iconic LEGO sets and themes. Wooden duck, wooden fire truck, Automatic Binding Bricks (house), Town Plan Truck, first LEGO train set, Yellow Castle, first DUPLO bricks, first Technic set (forklift), Galaxy Explorer, DUPLO train, Black Seas Barracuda, DUPLO farm, Technic Space Shuttle, Mindstorms, LEGO Bionicle Microfig (depicts Bionicle Tahu), Ninjago, Treehouse Ideas, LEGO Technic Crane and Emma's House from LEGO Friends.