h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

one of the best bits of geographical confusion i can remember was in the kevin costner 'robin hood': he gets off the boat at the white cliffs of dover, walks a couple of metres, and suddenly he's on hadrian's wall. teleportation, anyone?

An excellent example of this actually working, if you're not in the know about the locations, is the opening episode of Porterhouse Blue - Ian Richardson, as the new college master, processes past King's College Cambridge, arrives at the college gate which is really on the north side of Ely Cathedral 15 miles away, and walks into the college courtyard which is Apethorpe Hall near Peterborough - about a fifty mile journey in two minutes, and seamlessly edited.