221B Baker Street
221B Baker Street is the fictional London residence of the detective Sherlock Holmes, created by author Arthur Conan Doyle. The address could indicate an upstairs apartment (hence the B) of a residential house on what was originally a Georgian terrace. The B may, however, refer to the whole house. The street is considerably less narrow than is portrayed in some film versions of Holmes’ adventures and is a substantial and busy north-south thoroughfare, which is at least as congested now as it would have been in Holmes’ day.