London Underground

The London Underground is a system of trains running underneath London.

The Second Doctor seemed to believe the Underground was only built after Victoria Waterfield left Earth in 1866. (DW: The Web of Fear)

During World War II, a military transit camp was constructed in Goodge Street station. The rooms and corridors would remain in place, shut off from public access, for decades after the war finished. (DW: The Web of Fear)

The platforms and tunnels of the Underground were used by the Great Intelligence to pull in the Doctor and his companions Jamie McCrimmon and Victoria Waterfield in the TARDIS and have them attacked by its Robot Yetis. (DW: The Web of Fear)

There was a hidden elevator leading from one Underground station to a top-secret nuclear bunker under Whitehall. (DW: Invasion of the Dinosaurs)

Sarah Jane Smith once saved the Underground from a terrorist attack. (BFSJS: Test of Nerve)

The Doctor visited Aldgate underground station because it passed close to the chamber where the Water Hive were holding their prisoners. (TDA: The Feast of the Drowned)

There are parts of the Torchwood Hub which were built in a similar style to the old underground stations. (TW: Everything Changes onwards)

In the 22nd century, a disused underground station was used as a base for resistance fighters against the Dalek occupation. (DW: The Dalek Invasion of Earth)

Behind the scenes
In 2007 BBC Three did a London Underground night in which they broadcast episode 1 of The Web of Fear.