Atoniumummnumum*
if memory serves

*actual name may be smaller
( matsimpsk, Wed 20 Aug 2003, 0:34, archived)

Atomararium
Atomitomicron
Atomotron

Something like that
( wayward., Wed 20 Aug 2003, 0:38, archived)

indeed
it's the atomium, in Strassbourg
(sndmn, Wed 20 Aug 2003, 0:39, archived)