How can people recognise the building easily,

compared to other building’s shapes?

There are nine spheres representing atoms.
Discussion:
The Atomium was designed by a Belgian engineer Andre Waterkeyn to represent a single unit of iron crystal magnified 165 billion times. There are 9 spheres representing atoms which are connected by tubes with escalators and lifts. Each sphere is about the size of a large apartment (18 m diameter).
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