Atomium, Brussels, Belgium

Built originally for the 1958 Brussels World’s fair, the 102-m high Atomium was designed by André Waterkeyn and architects André and Jean Polak. The stainless steel clad spheres are connected in such a manner that in a whole it forms the shape of a unit cell of an iron crystal.
Six of the nine spheres are accessible to the public. The central tube in the structure contains a fast elevator which allows 22 people to reach in 23 seconds.