I wouldn’t make a special stop to visit this, but it is a nice stop when you’re in the neighbourhood (Brussels).
It was build for the 1958 world (universal) exhibition. The Atomium represents the atoms and their connections in a metal molecule (correct me if I’m explaining it wrong here). It was closed for renovations in 2005.
There’s a movie theater with a few very big screens next to it, and a little ‘village’ with (to expensive) bars and restaurants so it might be nice to spend an evening there, which is what we did.

**Edited 23/02/06*
It’s open again, and it’s been cleaned… so now the Atomium is very shiny, not like the foto.