There are only a handful of science fiction shows in the world that can boast that their primary alien villain is embedded so much in to the national consciousness that its image can be placed on a signpost. That is certainly the case with Doctor Who, which has been on British TV screens for an amazing 49 years (with one hiatus). If you need to find the location of the brand new permanent Doctor Who Experience exhibition dedicated to the show in the docklands of the Welsh capital Cardiff all you have to do is follow the Dalek signs....
