Looks amazing indeed. It's Miniatur Wunderland in Hamburg, Germany (
website in english and a
wiki page) its 1:87 scale H0
Haven't been there myself yet, but who knows...
When you're in Europe anyway, don't miss
RailZ Miniworld in Rotterdam, The Netherlands.
I've been there in spring 2011, quite nice I must say, especially with the behind the scenes tour.
They as well build it in a 1:87 H0 scale.
Near Rotterdam is the city of The Hague, which hosts
Madurodam,
a miniature Netherlands at the scale of 1:25, trains, planes, boats and cars included. (
wiki)
You can find loads of pictures and videos via google/youtube on both RailZ Miniworld and Madurodam.