Millenium domes

In a nutshell a 'wonderbra'.
Looking from the outside everything looks big and exciting, much like the millenium dome.
But once inside you're massively disappointed, and soon realise that it's nothing you're going to be writing home to your mates about.

Bloke 1: Epic knockers!
Bloke 2: it's a farce, they're millenium domes.