Greenford was a suburb of London, in the Borough of Ealing.
Ace used to go to Greenford disco. (TV: The Curse of Fenric, PROSE: Timewyrm: Apocalypse)
The Fifth Doctor and Nyssa visited Greenford at the time the series Surrender, Earthlings! was being aired. The Doctor claimed that at least three unsuccessful invasions of Earth had originated there or nearby, and that it had always been a target for cosmic phenomena due to a combination of ley lines and temporal anomalies. Nyssa thought it was ugly. (PROSE: Not So Much a Programme, More a Way of Life)