HI Guys,
Recently, I's looking for a LW airplace called "Campagne" as written around in many captions.
Well, I don't know a place called Campagne in France, Google doesn't know too.
Later, I did find it was in Calais surroudings. Bingo! There is 895 parish in Pas-de-Calais and four of them are called Campagne-something:
Campagne-lès-Guînes
Campagne-lès-Wardrecques
Campagne-lès-Hesdin
Campagne-lès-Boulonnais
So, which one was used by LW?
You must note that "lès" is written with an accent above the "e". "Lès", in french, means "Close by" (you can find "lez" as alternative spelling); If you write "les" it turns to be a plural article. Word is different, meaning is different.
It does happen the same thing with Guînes (recent spelling for Guisnes) and Pihen.
When talking about Guînes and/or Pihen, are you (those who write captions), are you talking about Guînes or about Pihen-lès-Guînes (eventualy about Campagne-lès-Guînes 
) ? Both places are different but two different airplaces?
Going deeper Pihen comes from old Frank word Pitheim. Then complete place name means "The pit place by Guînes".
Eventualy, there is a place in the surroudings called PIHEM!!!!! with an "m"!
Fortunatly there is nothing about some "Campagne-lès-Pihem(n)" 
Regards,
Franck.