A cursed squire, a spectral hound and a moor that swallows ponies: Conan Doyle's Sherlock Holmes novel, serialised in The Strand Magazine in 1901–02, is set largely on Dartmoor, and several of its places have real counterparts.
The route runs from the grave that may have inspired the legend and the ten-thirty train from Paddington to the convict prison at Princetown, the mire, the tors and the Stapletons' house. Baskerville Hall and Merripit House exist only in the book, so their pins mark a stand-in or nothing at all.
The BBC's Sherlock Holmes and his flatmate, army doctor John Watson, solve crimes in present-day London, from a killer's phone traced to their own doorstep to a dominatrix with compromising photographs and a criminal who cracks the Crown Jewels from his mobile. Six stops follow the first three series in order: the 221B front door on North Gower Street, the Baker Street museum, a summons to Buckingham Palace, Moriarty's Tower heist, the hospital rooftop finale and a bomb under Parliament.
Most stops are London landmarks you can see from the street; the 221B door is a private house, and the palace, Tower, hospital and Parliament appear as the show's story settings.
A chance meeting at the Criterion Bar sends an army doctor just back from Afghanistan to a laboratory at St Bartholomew's Hospital, where a stranger grips his hand and observes: "You have been in Afghanistan, I perceive." Within days Dr Watson has moved into 221B Baker Street, the address where many of the stories begin, and off runs the canon: four novels and 56 short stories, all but one set between 1880 and 1914.
This route walks Holmes's London in the order the stories appeared: the Criterion where Watson met Stamford, the hospital of the famous first deduction, the Baker Street rooms that did not exist when Doyle wrote and are now a museum, Scotland Yard's Victorian headquarters on the Embankment, a society church where a bride vanishes, a silent club on Pall Mall, and the Underground station where a body fell from a train roof.