The World Wildlife Federation advertising campaigns consistently utilize their existing surroundings very well.
Here is the latest example of their campaign ads, using a paper dispenser with South America cut out, and green foil to tint your view… “clearly conveying that with every piece of paper you take, you’re taking away from the greenness of South America. How multisensory and engaging beyond a simple sticker/poster.” (NotCot.com)
The second example is an amazing use of shadows on a billboard, demonstrating rising water levels. Click here for a Youtube video of the billboard in action. Both ads are designed by the prestigious Denmark based Saatchi and Saatchi.