I'd have said western Germany.
http://en.wikipedia.org/wiki/Western_Germany
Das war nicht falsch! Hilfreich wäre es aber schon, das Gebiet etwas einzugrenzen. Nähe Köln, Düsseldorf, usw.
West Germany is not wrong, but it used to be used for the Federal Republic before reunification. I'd say which was the nearest city, as NRW is quite big!
Wikipedia is useful for translations of things like this:
http://en.wikipedia.org/wiki/North_Rhine-Westphalia
Just change the language in the column on the left!
EDIT: Übrigens, Schade, dass ich in München so weit weg bin!
Bock hätte ich schon!
