For those of you who aren't Sylvia Plath fans, 23 Fitzroy Road, London is the address of the house where she died in 1963.
I actually got a chance to visit it in 2012. And by visit I mean I made my sister and a friend wander around Primrose Hill with me at 9pm until we found the house. It has a black front door and the sign to the side of the door only mentions that William Butler Yeats lived there. We also visited the other house on Primrose Hill where she lived for a longer time and which has the sign actually stating that she lived there. They're only a few blocks apart from one another.
Real people live in these houses now so you can't wander around inside them. They're all modern and renovated. I guess it doesn't really make sense to leave whole residences vacant out of literary sentimentality. Especially not in a nice part of London.