London Underground
From Tardis Wiki, the free Doctor Who reference
The London Underground is a system of trains running underneith London. In around 1970 the platforms and tunnels of the system were used by the Great Intelligence to pull in the Doctor in the TARDIS and have them attacked by it's robotic yetis.(DW:Web of Fear)
Sarah Jane also has to save the Underground from a terrorist attack in Test of Nerve.
