The game's afoot as armchair detectives mark Sherlock Holmes Day

SCHATTENHALB, Switzerland (AP) — From 221B Baker Street in central London to a cliffside waterfall in the Swiss Alps, generations of armchair detectives are celebrating International Sherlock Holmes Day on Friday.

Fans will mark Sir Arthur Conan Doyle 's birthday in tribute to the author and his most famous character whose adventures continue to shape popular culture around the world.

The celebrations began earlier this month when — sporting Victorian capes, deerstalker hats and period gowns — enthusiasts from the Sherlock Holmes Society of London traveled to Switzerland 's Reichenbach Falls to reenact one of literature's most famous fictional death scenes.

The fateful confrontation between Sherlock Holmes and his nemesis Professor James Moriarty shocked readers of “The Final Problem” and appeared to bring one of literature’s most beloved detectives to an end.

In the original 1893 story, Holmes disappears over the edge of the falls with Moriarty, leaving his sidekick, Dr. John Watson, to discover a farewell letter near the water. Conan Doyle — who was born on May 22, 1859 — intended the scene to permanently kill off Holmes because he feared the detective stories were overshadowing what he considered his more serious historical writing.

At the time, readers canceled magazine subscriptions, wore black armbands in mourning and protested against Holmes’ death. A decade later, Conan Doyle reversed the decision and brought Holmes back in “The Adventure of the Empty House,” revealing that the detective had staged his death and survived the falls.

The Sherlock Holmes stories helped establish many of the conventions of modern detective fiction. Between 1887 and 1927, Conan Doyle wrote four Holmes novels and 56 short stories, introducing techniques such as forensic deduction, close observation and logical analysis that later became standard elements of crime fiction.

The stories have since been adapted for the stage, screen and in comic books around the world, with Jeremy Brett, Basil Rathbone, Christopher Lee, Robert Downey Jr. and Benedict Cumberbatch starring in portrayals.

British actor Hero Fiennes Tiffin stars in the latest iteration in Amazon Prime’s new prequel series “Young Sherlock,” created by Guy Ritchie and released earlier this year. A second season is in the works.

At 221B Baker Street, the Sherlock Holmes Museum has drawn visitors since it opened in 1990 with curiosities including Holmes' violin and chemistry set, as well as a revolver resting inside a hollowed-out book.

Holmes, according to the stories, lived at the Georgian townhouse between 1881 and 1904 and shared the residence with Watson. But 221B didn’t actually exist when Conan Doyle was writing: Baker Street numbers didn’t reach that high at the time.

The museum, physically located between 237 and 241, had to be granted special permission by Westminster City Council to bear the renowned number.

“It has to be the most famous address in the world, I would say,” tour guide Paul Leharne said. “No matter what reincarnation Sherlock Holmes is going to take, he’s always going to be living at 221B Baker Street.”

With theatrical poses, exaggerated acting and black cloaks billowing in the mountain spray, members of the Sherlock Holmes Society of London on May 3 reenacted the struggle between Holmes and Moriarty at Reichenbach Falls.

Founded in 1951, the society brings together readers, collectors, academics and enthusiasts of Conan Doyle’s work. The trip to the Reichenbach Falls followed part of the route described in “The Final Problem.” Members traveled through Switzerland in vintage buses before boarding a cog railway that climbs steeply toward the waterfall.

The Reichenbach Falls became one of the most famous locations in detective fiction after Conan Doyle visited the area during an 1893 trip.

Philip Porter, an author and publisher who starred as Sherlock Holmes in the society's reproduction, said the setting itself remains central to the stories’ appeal.

“It’s a pilgrimage,” he said. “It’s a very dramatic setting: The sound, the backdrop, the music behind us of the cascading water.”

Peter Horrocks, who played Moriarty, said the return to normal life after spending several days in a villain's costume can be tough. “It’s a strange feeling, getting out of these clothes,” he said. “You do start to inhabit the character that you’re playing after a while.”

Fielder reported from London.