Cairo

Cairo was a city in Egypt.

In 1911, Dr. Warlock, a friend of Marcus Scarman, made some inquiries in Cairo about Marcus. (DW: Pyramids of Mars)

The Doctor, along with Benny visited Cairo in 1798. (NA: Set Piece)

Cairo was believed to have been the home of Erimem, a companion of the Doctor from Ancient Egypt. During the an encounter with the plants of YT45, the Doctor saw the fantasy world of his companion, Erimem, as the ruler of an amalgam of the many worlds she has visited along with her home, naming it New Cairo. (BFA: The Mind's Eye)

Real life Facts

 * Nicholas Courtney, who played Brigadier Lethbridge-Stewart, was born in Cairo.