Its nine 18-metre-diameter (59 ft) stainless steel clad spheres are connected in the shape of a unit cell that could represent an iron crystal magnified 165 billion times.

The name Atomium (pronounced /əˈtoʊmiːəm/ ə-TOH-mee-əm) is a portmanteau combining the words atom and aluminium, the metal with which the spheres were initially covered.

[10] With the Atomium, Belgium wanted to highlight and promote the post-war ideal to peacefully apply atomic research and other advancements in technology in order to improve lives and serve the betterment of mankind.

[11] The Atomium's nine 18-metre-diameter (59 ft) stainless steel clad spheres depict nine iron atoms in the shape of the body-centred cubic unit cell that could for example represent α-iron (ferrite) crystal, magnified 165 billion times.

In January 1955, a first project was presented by the engineer André Waterkeyn, director of the economic department of Fabrimétal [fr], the Federation of Companies in the Metal Fabricating Industry (now known as Agoria).

The foundations were launched in March 1956 and the building, erected by the Jambes-Namur Construction Workshops, was completed less than a month before the inauguration of Expo 58, on 17 April 1958.

The central tube contains the fastest lift in Europe of the time with a speed of 5 m/s (20 ft/s),[2] installed by the Belgian branch of the Swiss firm Schlieren (subsequently taken over by Schindler).

[13] The Atomium, designed to last six months, was not destined to survive the 1958 World's Fair, but its popularity and success made it a major element of Brussels' landscape.

The renovation included replacing the faded aluminium sheets on the spheres with stainless steel, as well as building a new reception pavilion with a boomerang-shaped roof.

At the foot of the building, the roundabout was redeveloped into a concrete esplanade lined with continuous benches and a large step leading to the north-east.

[2] In addition, the German industrial designer Ingo Maurer created lighting objects and installations for the interior of the building.

[2] Likewise, while the subject of Atomium was chosen to depict the enthusiasm of the Atomic Age, iron is not and cannot be used as fuel in nuclear reactions.

The Atomium, with over 600,000 visitors per year, is the most popular tourist attraction in Brussels, and acts as an international symbol of both the city and country.

[24][25] SABAM responded that they would make an exception for 2008 and that people could publish private photographs for one year only on condition they were for non-commercial purposes.

[27] From the Atomium's website, the current copyright restrictions exempt private individuals under the following conditions:[28] This is the case where photographs are taken by private individuals and shown on private websites for no commercial purpose (the current trend for photo albums).In accordance with legislation, usage rights for the image of the Atomium would naturally extend to 1 January 2076, in other words, the seventieth anniversary of André Waterkeyn's death.In the summer of 2015, Belgian political party Open Vld, part of the then-ruling Michel I Government, proposed a bill to enable freedom of panorama in Belgium.