The Sherlock Holmes, 10 Northumberland Street, WC2 - as close to Northumberland
Avenue as you are likely to get, at least the name is similar. Apparently,
this pub is a big haunt with Sherlock Holmes societies that arrive all summer
to pay tribute.
The pub contains a tableau of Holmes' study as it appeared in 'The Empty House'. It used to be part of the Northumberland Hotel, a place well liked by Sir Arthur Conan Doyle and which was also mentioned in 'The Hound of the Baskervilles'
Cross Northumberland Avenue, head back up to Trafalgar Square and bear left down Whitehall.