I did a post a while back that featured this photo I took in Eindhoven Netherlands, if that's an issue for the contest please let me know and I'll remove it. If not then this is the Trudo Vertical Forest building. It was one of the coolest uses of nature in architecture that I've seen in a city. I couldn't tell if each of the outcroppings was a balcony that was accessible to the residents or if they were just a design feature of the building, but each had a tree planted on it. I thought it was a smart idea, and quite beautiful really.