Most of the Cumberbatch-Freeman series is shot in Cardiff . “Steven Moff at, who is the producer of both Sherlock and Doctor Who decided to shoot in Cardiff . All the shots fi lmed indoors at 221 Baker Street are shot at a studio here. Most of the exterior locations are also within 20-30 miles of the studio in Cardiff because it’s just easier for the crew. They travel to London only if they need a very specific location,” says Michael.In the original stories, Mycroft is meant to live on Pall Mall, just opposite the Reform Club. In the BBC series, the exterior of the Diogenes Club is shot at 10 Carlton House Terrace, which used to be the home of the British Prime Minister William Gladstone. For The Blind Banker, the second episode of the BBC series, the makers shot a few scenes in the very touristy Trafalgar Square. “It’s very expensive to close down the Square during the day so these scenes must have been shot very quickly and with a bare-minimum crew. The crowd in the scene would be the regular public. If you look closely at the scene where Cumberbatch and Freeman walk up the stairs of the National Gallery, you can see the faces of members of the public who have recognised the actors.