Thanks guys, it was somewhere between Monaco and Nice, along the coast. I think it's Villefranche sur Mer, but I can't be sure. If anyone cares to name the place, I'd love to hear it.
Anyway, it was such an amazing vantage point, I pulled over and stood there in awe for like 10 minutes.
I wish I had a better camera. The one I had doesn't do this picture justice, but it's still better than nothing :)