In 2008, Richard Lazarus presented his rejuvenation device in Southwark. It mutated him into a monster which killed several people. he again hid in the cathedral's crypts as he had done during the Blitz. Martha Jones and the Tenth Doctor found him and he chased Martha up the bell tower. The Doctor used the cathedral's organ to distract him and he fell to his death. (TV: The Lazarus Experiment)
↑By combining the London street map seen in The Lie of the Land, and the various birds-eye view shots of the same area shown throughout the episode, with the map of London boroughs seen in TV: Revenge of the Slitheen, these locations are definitively shown to be located in Southwark.