I love this photo so much that I couldn't resist re-posting it here. The full size picture can be found at the http://www.brueckenbau-links.de/ website: bridge-in-bridge.
Someone once told me it must be photoshopped. Well, you be the judge. I have evidence that it isn't.
The maintenance nightmare doesn't bear thinking about. When it comes time to demolish one of the two bridges, it would be interesting to see how they do it without disturbing the other.