The Atomium is a monument in Brussels, Belgium, built on the occasion of the Universal Exhibition of 1958 and representing the conventional cell of an iron crystal magnified 165 billion times.
The nine spheres that make up the monument are not a reference to the nine Belgian provinces of the time. They represent the nine constituent atoms of iron crystal. The original designer of the monument was conceived as a reference to the science theme of Expo ’58, and in particular the science of the atom under development at this time, not as a reference unit the nine provinces of the kingdom that was a coincidence.
In April 2006, Belgium issued a commemorative 2-euro coin representing the Atomium on the occasion of its reopening