Just found the first mention of Essex in
Doctor Who, In the 1964 story
The Keys of Marinus Ian Chesterton looks at the Tardis scanner showing the sandy planet of Marinus and declares "Well, it doesn't look like Southend!" Colchester also gets a mention in the Matt Smith era when Amy and Rory move there and the cybermen turn up, while Donna Noble also reveals to David Tennant's Doctor that she learned to whistle up West Ham.
