Q is for Quarry: Filming to a strict budget can be difficult so, when faced with yet another script demanding an alien location, the BBC would usually decamp to a desolate quarry in Dorset and pretend that they were in fact light years away. Where would science fiction filming be without quarries? I guess pretending that all alien planets look like deciduous forests or bleak moorland instead, those being the other two favourite stock locations. The genius of Doctor Who scriptwriters led them to set one particular story (Sarah-Jane Smith's last) in a real quarry, thereby confusing all the viewers who naturally assumed that the Tardis had landed on yet another featureless alien world again.
R is for Regeneration: If one thing has helped Doctor Who to live long and prosper, it's the concept of regeneration. The show could have spluttered to a grinding halt in 1966 when William Hartnell asked to leave, but the production team dared to film him magically turning into Patrick Troughton after a particularly tiring battle with the Cybermen, and so the series was saved. It sure beats Bobby Ewing emerging from the world's longest shower, for continuity purposes at least. Patrick became Jon as a Time Lord punishment, Jon became Tom after overdosing on radioactive spiders, Tom became Peter after falling off a radio telescope, Peter became Colin after running out of emergency antidote and Colin became Sylvester very very suddenly because Michael Grade hated him. And then Sylvester became Paul because he made the enormous mistake of going to America...
S is for San Francisco: After a seven year gap, Doctor Who was reborn as an American TV movie in 1996. The film had everything - money, expensive sets, regeneration, a new Doctor, two new assistants, the Doctor's first ever love interest, a foreign location, the end of the world (again), even a new Master. Everything that is except a decent plot. By the time Paul McGann emerged from a hospital morgue there was only an hour of the film left, most of which time he spent trying to remember Who the hell he was, pursuing a shapely surgeon, or just riding around on a motorbike without a helmet. Virtually all of the action took place after dark so the San Francisco location was completely wasted and, well, the whole thing just lacked drama. And monsters. They never made a second movie.
T is for TARDIS: Another flash of brilliance from the original Who design team - a state-of-the-art spacecraft that's bigger (and cheaper) on the outside than the inside. The TARDIS (Time And Relative Dimensions In Space) malfunctioned in episode 1 and has been stuck looking like an old 1960spolice box ever since. The Doctor's Type 40 suffered from erratic steering (usually within the first two minutes of each story) and in 1981 managed to end up on the Barnet by-pass next to London's last remaining police box.