It looks a lot like
this bridge. According to the website (the tags, anyway), the bridge is in or near a village called Vence, but it's hard to fine anything else on it. After looking a little more, it might be the Viaduc de Saint-Paul (
link to another photo (http://www.flickr.com/photos/18911612@N08/5945368760/ - broken link)). One more sort of confirming that
it's near Vence (http://www.flickr.com/photos/bobbyzny/6212730999/ - broken link).
Seeing as her Grandfather was stationed in France, it would certainly make sense. Also, there are 6 arches on the bridge in your photo and 6 on the full photo of the bridge that I linked to. The ornamentation under the railing is very similar as well. There are a few things from leading me to 100% certain though.
1) The light posts on the other photos aren't visible in your photo. That's not a deal breaker as they could either be down when he took the photo OR they may just be blending into the background (it's hard to tell).
2) The picture I linked to (the older one) has a vertical feature on two of the columns (you can see it to the left and right of the bridge) that isn't on the picture you posted. It could be that the angle of the photo is from the opposite side and therefore not visible from the photo you posted. I think this is the case seeing as your photo has a mountain rising in the back and the aged photo I linked to doesn't. The other two photos don't show that feature.
3) The aged photo I linked to has what appears to be wooden posts sticking out of the arches. Neither your photo (not the other two) appear to have the same feature. I'm assuming it was wood and is no longer there.
Anyway, I'm still fairly certain that the bridges I posted are the same. It all seems to make sense.