"huge, detached wedding cake-style mansion on the other side of Holland Park Avenue"
Holland Park
Creative Commons AttributionHolland Park - Credit: Esteban

On the "other side of Holland Park Avenue" lies Holland Park itself, home to an opera company, a troupe of peacocks and a rather fine orangery.  This is the heart of Kensington, a very smart and pleasant part of London.

The late Harold Pinter was a much admired English playwright and actor.

Google Map