The Chandos, Leicester Square
A mate of mine recently showed me an iPhone app called "Smith Finder" http://bit.ly/TxB5ki that features this pub and a load of other interesting old pubs. Our "couple of pints" ended up turning into a bit of an impromptue pub crawl!
29 St Martin's Lane, Leicester Square, London, WC2N 4ER
Come out of Leicester Square tube station, head down the Charing Cross Road in the direction of Charing Cross. When you get to Martins Place cross the road onto St. Martins Lane and The Chandos is right in front of you opposite Corney and Barrow.