England
From Tardis Wiki, the free Doctor Who reference
England is a geographical region of Earth in the country of United Kingdom. It is frequently visited by the Doctor, who has adopted much of its customs, dress, and other cultural elements. The capital of England is London, which is the home of several of the Doctor's companions including Rose Tyler, Martha Jones and Donna Noble. It's also a significant site for many Doctor Who stories.
In one alternate universe where the Doctor died while preventing the Racnoss' return, London was mostly destroyed in a horrible explosion by the Titanic crashing into it.