1.The villain’s mansion, called Appledore, is owned in real life by one of the country’s most successful engineers - but millionaire Sir David McMurtry does not live there because his wife thinks it is too flashy.
3.Nicknames Chinese fans have given the two stars of the hit drama: Curly Fu and Peanut.
Cumberbatch's Sherlock is known as Curly Fu – Curly because of the coils of locks he sports for the role and Fu which is a shortening of Holmes in Chinese.
Freeman, who plays John Watson, is called Peanut for the rather more mundane reason that the actor's name in its Chinese form – Hua Sheng – sounds a lot like the Mandarin for the nut.
4.The 370 sq ft one-bedroom flat above Speedy’s Cafe, which is in fact about a mile away from Baker Street but doubles as Sherlock’s home for exterior shots, was available for rent in early 2012 for the price of £330 a week.
5.Speedy’s Cafe, is a real café on Gower Street, near Euston – the BBC’s stand-in for 221b Baker Street. In the Sherlock pilot it was run by Una Stubbs’s character and named Mrs Hudson’s Snax n' Sarnies, but that idea was swiftly dropped. The fans who flock there from all over the world can now enjoy specially created Sherlock-themed snacks,
- Sherlock wrap (chicken, bacon, cheddar cheese, lettuce, peppers, red onion, cucumber, chilli sauce – all "wrapped up as tightly as Sherlock’s personality")
-Watson Wrap (roasted vegetables, spinach, tomatoes, spring onion, Brie, sour cream – "safe, warm, and comforting, like his personality").
-A Moriarty sub is reportedly in the works.
6.In 2006, well-known Holmes enthusiast Mark Gatiss was asked to address the Sherlock Holmes Society's annual dinner at the Houses of Parliament. Gatiss, who brought along Steven Moffat as his guest, told the audience about a meeting at the BBC to discuss the possibility of resurrecting Arthur Conan Doyle's creation for a Christmas special. He and the Corporation failed to reach an agreement, but as he "raced round the endless circular corridors, frothing at the mouth at what these philistines might be planning", Gatiss bumped into John Simpson, recently returned from Kabul. “As he passed me,” Gatiss explained, “I touched him on the arm and whispered: ‘You have been in Afghanistan, I perceive’.” This gave him the seed of an idea, which he and Moffat subsequently grew into a modern-day Sherlock: "A young army doctor, wounded in Afghanistan finds himself alone and friendless in London," he teased the group. "Short of cash, he bumps into an old medical acquaintance who tells him he knows of someone looking for a flatmate. This bloke’s alright but a little odd..." Gatiss was effectively pitching his and Moffat’s Sherlock to the toughest crowd imaginable, and they approved.
7.The Mind Palace, as introduced in the Sherlock episode, “The Hounds of Baskerville,” does not come from the Holmes canon. The memory technique, however, has featured in literature before, most memorably perhaps in Thomas Harris’ Hannibal novels.
Further references to Hannibal can also be spotted in this episode, with Sherlock even pointing out that Major Barrymore keeps a copy of Hannibal on his bookshelf at Baskerville.
8.Although most Sherlockians agree that Dr. John H. Watson’s middle name was “Hamish,” this was not a detail revealed in any of Conan Doyle’s stories. The idea that Watson’s middle initial stood for “Hamish” was put forth by Dorothy L. Sayers, in her 1943 essay, ‘Doctor Watson’s Christian Name.’
Sayers’ theory is based on what would appear to be a typo in Doyle’s ‘The Man with the Twisted Lip,’ in which Watson’s wife refers to him as “James,” instead of “John.” As “Hamish” is the Scottish version of “James,” Sayers makes the suggestion that Mrs. Watson was simply middle-naming her husband, and that “H” thus stands for “Hamish.”
9.Louis Oliver, who played young Sherlock in "His Last Vow," wore contact lenses to make his eyes a Cumberbatch shade of blue for the part. Louis is the son of writer/creator, Steven Moffat, and producer, Sue Vertue.
10.Moriarty's waltz as he breaks into the Crown Jewels in "The Reichenbach Fall" was not scripted, but added by actor, Andrew Scott.