CubicFun 3D Puzzle MC-Series Great Wall of China A fun and challenging 3D puzzle of The Great Wall Constructed using CubicFun's unique slotting system, Puzzle: Similar building toy like Lego, Difficulty Level: 5, Number of Pieces: 75, Age: 12 Years And Up Construction Time:150-180 minutes Great holiday gift for young and old, Develop logical thinking, Best for schools, Day cares and Educational institutions, fun and attractive, beautiful souvenir.