A popular question asked at Hercule Poirot Central is: where in London is Whitehaven Mansions, Hercule Poirot's home as seen on the television series "Poirot"?
Such a question deserves an article, c'est vrai.
It is found on Charterhouse Square in London. Many buildings surround the square, but the residential building known as Florin Court (known as Poirot's "Whitehaven Mansions") is located on the eastern side of a park there. Finished in 1936, the building houses a swimming pool in the basement and a roof garden (as seen on satellite images). Florin Court (and Charterhouse Square) is just north of the Museum of London (at London Wall). The Museum of London's postcode is EC2Y 5HN, whereas it is known that Charterhouse Square's postcode is EC1.
For visitors not familiar to London, Charterhouse Square is just west of Goswell Road/Aldersgate Street and one block north of Beech Street. One can always go to Holborn Circus, and from there take Charterhouse Street in a northeast direction up to the Square.
Another thing: if you're near the Barbican Centre, home of the London Symphony Orchestra and the Royal Shakespeare Company, you know you're close. The Barbican Centre is adjacent to the Museum of London.
There are some excellent photos of Florin Court (and Charterhouse Square) on the flickr site. The following satellite images below are taken from Google Earth. I have labeled a few places for idea of proximity/location. To enlarge a picture below, simply click on it.