This window is in a cottage in a small town near Blackheath called Medlow Bath.
It's much smaller than Blackheath and its main claim to fame is a large hotel called the Hydro Majestic which sits on the edge of a cliff and was once a must go to place for honeymooners and other holiday makers taking in the bracing air and scenery.

I had always assumed that this small cottage was a toll house, but google won't confirm this.