Guernsey

Guernsey was one of the Channel Islands in the English Channel. In 1941, when the Channel Islands were held by the Nazis, Guernsey was visited by the Seventh Doctor, Bernice Summerfield, Roz Forrester and Chris Cwej. (NA: Just War)

In an alternative timeline in which Sarah Jane Smith died on 13 July 1964, Maria Jackson, the only person to remember the proper timeline, searched for Sarah Jane on the Internet in 2008 and discovered that there was a woman of the same name who played football on Guernsey. It is highly likely that this individual existed in the proper timeline as well. (SJA: Whatever Happened to Sarah Jane?)