221B Baker Street was the fictional address of Sherlock Holmes and Doctor John H. Watson in London, England. Located in a multistory building, it was the residence of Holmes in the 1890s. It included a sitting room in which Holmes kept objects of significance to him and a drawing room. The furniture in this room was of the Victorian era.
Aboard the USS Enterprise-D, this building was recreated for Sherlock Holmes Program 3A used by Data and Geordi La Forge in the 2360s. In 2365, before entering the program, Data informed engineer Clancy that La Forge could be contacted at 221B Baker Street, which left her startled. In 2369, it served as the meeting place between Captain Picard and Professor James Moriarty. (TNG: "Elementary, Dear Data", "Ship in a Bottle")