The three-part Londinium episode during Batman's third and final season ("The Londinium Larcenies", "The Foggiest Notion", and "The Bloody Tower") was the series' tribute to the Swinging London period of the 1960s. At the time of the show, everything British was "hot" in North America. Many aspects of London were parodied during the three episodes. The city's name is changed to Londinium, which was the name of an important trading and administrative centre of Roman Britannia, which was slightly smaller than the City of London where the modern British capital is now situated. Scotland Yard becomes "Ireland Yard" in the series. Carnaby Street becomes "Barnaby Street". Fleet Street, the city's press district, is changed to "Bleet Street". The prime minister is called the first minister. There is a jokey reference to The Beatles when Bruce Wayne refers to a drum-playing Dick Grayson as "Ringo."
When Batman and Robin were asked to investigate a series of daring robberies in Londinium, they knew it would be dangerous fighting the master criminal, Lord Ffogg on his own turf, so the Dynamic Duo decided that they had to even the odds. They loaded the Batmobile and lots of crime-fighting equipment from the Gotham City Batcave into a container and onto their steamship. When they arrived at the Londinium country manor house that Bruce Wayne had rented, Alfred quickly set up all the equipment in the secret dungeon underneath, and it became known as the Londinium Batcave. This new Batcave even had a handy isolated exit that led directly to the Queen's Highway.