These cubes are not as popular as lego, but will teach kids some of the same concepts. I like the fact that they all nest into each other. That makes them easy for kids to store and they take up less space.
Dado combines art and science as you explore architectural principles… proportion, balance, structure and color. A new twist on classic building blocks, Dado engages your imagination as the slits on each cube are interlocked to create an unlimited number of three-dimensional structures. Constructed horizontally, vertically or nested together, Dado invites visual spatial development and problem solving through design-centered, attention-grabbing fun!
Dado cubes are loaded with educational benefits. Each set features 10 cubes, scaled from 1 inch to 5 inches, capable of building structures over 32 inches high!
I found them at Sparkability.com for 24.95 U.S. for kids 3