### Clue: Barbara Castle? (7)
### Answer: WINDSOR 
 ### Explanation: Definition: Barbara,Castle
  Double defn: 1st: Barbara, actress's stage name, in the Carry On… series of films in the 60s and 70s and later in the TV soap opera EastEnders; and 2nd: English royal residence,castle.  The question mark denotes the ambiguity with Barbara Castle, late Baroness, former Labour Party politician and Cabinet Minister.