Thank you, MisterMattias, for your comment. I did, as a matter of fact, take more than a dozen pictures during the sunset (nine of which you can see here:http://www.pbase.com/bollag/ponte25abril ), but zoomed, alas, in and out between shots instead of keeping focal length and angle steady over the whole period; too bad! db.
A great scene both at day and night time. Maybe you should set up your camera here for a time-lapse movie, I bet it'd be a good place to see the sun setting and all the city lights come to life. /MisterMattias