Oh a secret pub Jeane, tucked away behind what used to be called The Brecknock Arms. It was/is called The Admiral Mann and served McMullens ale. (the other I know is the Nags Head at Covent Garden.)
On my first afternoon in London as a lad of 19 and not yet a Guinness drinker I had a pint of Worthington-E. "All beer passed by the management." It certainly tasted like it had, literally. McMullens too is more 'watery' than most real ales, but it does it's job wondrously. We used to take friends that thought they knew what was best about beer there and listen to them mock...and wait till they were on their third...oh yes, a separator of men from boys.
It's a nice enough little place;small front bar and roomy saloon at the rear (where the pipes are). There used to be a frieze around above the picture rail of whatever sea battle gave the gentleman his fame. Painted by the same chap that did a mural of Edinburgh Castle in the eponymous pub in the Caledonian Road which to me was rather out of perspective.
http://fancyapint.com/Pub/london/admiral-mann/3159