M25 motorway
From Tardis Wiki, the free Doctor Who reference
The M25 was a British motorway which circled around the city of London.
Mags was found scratched up and covered in mud on the M25 before she was moved to St Gart's Bankside Hospital for proper treatment. (AUDIO: An Alien Werewolf in London)
The M25 appeared on the Department's digital map of the home counties in 2050. (TV: The Bounty Hunter)