In 1958, Brussels was host to Expo ’58, the World’s Fair. The most famous structure left from the fair’s site is the Atomium, a 335-feet high model of the molecular structure of iron. To be precise, it’s a model that includes a unit of 9 iron atoms that forms the smallest repeating unit of a body-centered cubic lattice.
Like the image above, but balancing on one of its corners.
I can only show you that public domain image of an iron lattice, rather than an image of the actual Atomium, because images of the building are subject to very strict copyright regulations that prevents almost anyone from sharing photos of it. The only exception is for use in private online photo albums, or after asking for explicit permission, and then you still have to pay. So just use your imagination.
Although the Atomium is built to look like the molecular structure of pure iron, that’s not really what it’s made of. When I visited, in 2000 or 2001, the outer shell was made of aluminium – an entirely different metal from iron. After being visited by thousands of tourists over the years, the Atomium started to look a bit weather-worn, so in 2004 the entire structure was renovated and the aluminium shell was replaced with stainless steel. Stainless steel does contain iron, but other metals as well. Steel is an alloy of iron and carbon, and stainless steel also has chromium in it.
Stainless steel was invented in 1912 and patented in 1915. In the past 100 years it has been used to make everything from forks to building materials. It’s now used in so many iconic structures that the website of the Stainless Steel Centenary has several pictures on their site: the Thames Barrier in London, Cloud Gate in Chicago, the Wales Millennium Centre. Obviously not pictured: The Atomium. Because that’s not allowed.