Atomium is build in 1958 for Brussel's World Expo. It is located in Brussels, Belgium. Google Map
The building is 103 meters high. It has 9 spheres, each 18 meters in diameter.
The spheres are interconnected by tubes with escalators inside. The longest such connection is 35 meters.
The spheres are arranged in like the coners of a cube, with one in the center. It is the same structure of iron crystal.