- 221B Baker Street: The fictional address of Sherlock Holmes' residence. Filming for exterior shots took place at 187 North Gower Street, while interiors were filmed on a set at BBC Studios in Cardiff, Wales.
- St. Bartholomew's Hospital: Used for filming scenes set at St. Bart's Hospital, where Dr. Watson works.
- The Marylebone Hotel: Served as the exterior for 221B Baker Street in some episodes.
- London Underground stations: Various stations, such as Aldgate and Baker Street, were used for filming.
- The National Portrait Gallery: Used for scenes set at the museum.
- The Royal Institution: Featured as a location in some episodes.
- Cardiff: While most filming occurred in London, some scenes were shot in Cardiff, Wales, where BBC Studios is located.