221b Baker Street is the address of the fictional Sherlock Holmes and Watson, created by Arthur Conan Doyle (1859–1930). The building was built in 1815 and is listed.
In the stories, Mrs Hudson is the landlady of 221b. The restaurant is next door to the museum.
A huge copy of the 2009 UK first class postage stamp commemorating the 150-year anniversary of Conan Doyle's birth.
And around the corner on Marylebone Road, in the shadow of the dome of a much larger London attraction just visible on the bottom left, is the statue of Sherlock Holmes. It was commissioned by the Sherlock Holmes Society of London in 1999, and sponsored by Abbey National plc to commemorate its 150-year existence.
I didn't join the museum queue, but a link to a rather dramatic nine-minute video clip is below:
The Sherlock Holmes Museum