I would like to place the bridge on an office building. The bridge would be broken into parts of a monster/sea serpent/dragon to make it look like the creature is crawling up the side and weaving in and out of the building. No parts will have to be melted or altered, the body segments would be angular and would use the pieces to create the already bridge-like structure of the body segments. It will be like "mini bridges", climbing up the side of the building. It'll be painted green and use other smaller parts of the bridge as spikes on the outer part.
Inside the building, the color will be unchanged and the beams (2 on each floor) will be used as desks or shelving (since it's an office building). That way, the creation will be both practical and interesting to look at.
An idea for where to put this would be the old Goldman and Sachs building. It's plain, gray, boring and kind of depressing to look at. I feel as though this addition to the building will liven it up and bring excitement to the area. Not only would any sort of structure make the building seem happier, but the idea of a green serpent of some kind climbing up the side of it, let's people be imaginative. Not to mention that people would probably think that the crawling continues inside, even though in reality, it becomes plain desks and shelves.