Rebuildable You can build your own castle, and if you want to build something another or build it one more time just put the building into the water for a few minutes and than you can easily separate blocks and build again. Eco-friendly All of our parts are made from eco-friendly material. Natural gypsum and ceramic, non-toxic glue, carton. STEM Toy This toy created not only for a play but to improve your kid skills, like logical thinking, creativity, engineering, math, science, technology. Box includes: Instruction how to build the building from the fundament to the last level. Glue for connects all of the parts. Gypsum and ceramic block to build great structures. Fundament - the place where you should start to create your building.