Netley is a village in Hampshire, close to Southampton. The Royal Victoria Country Park was the old Netley Hospital; built after the Crimean War, and used extensively from 1863 to World War II. Watson was trained here before going to Afghanistan (A Study in Scarlet).

 

It is thought that Enoch J. Drebber was about to leave London and return to New York via Liverpool. (A Study in Scarlet)

 

Sir Arthur Conan Doyle lived at 12 Tennison Road, South Norwood, SE25 between 1891 and 1894. It is now an old people's home. It featured in an article in The Strand Magazine.

 

Pondicherry Lodge, Home of Major Sholto in The Sign of Four. Upper Norwood is a suburb of South London near Crystal Palace.