Southwark was a town in London.
The Globe Theatre was built in Southwark. In 1599, the only performance of Love's Labour's Won temporarily brought the Carrionites to Earth with the power of words, but William Shakespeare, aided by the Tenth Doctor and Martha Jones, devised his own wording to send them back. (DW: The Shakespeare Code)
Richard Lazarus was from Southwark. During the London Blitz, he hid in the crypts of the Southwark Cathedral. (DW: The Lazarus Experiment)
In 2007, Southwark was at the forefront in the brief Battle of Canary Wharf between the Cybermen and Daleks. Many casualties and damage occurred across the streets of Southwark. V. J. Ellison commented on the battle at a later date. (DWBIT: Doctor Who: Battles in Time Daleks vs Cybermen Special)
In 2008, Richard Lazarus presented his rejuvenation device in Southwark. It mutated him into a monster that killed several people. He was defeated by the Tenth Doctor in the Cathedral. (DW: The Lazarus Experiment)