Historic England is the organisation name, so the title should probably be
Historic England Aerial Photo Explorer.
There's a sizeable cluster north of London on there - trying to work out why, I suspect it may be the proximity to Bedford Aerodrome and the fact that it's a very farming centered area and aerial photos can be very useful to farmers.
Amazing! Makes me a bit sad to see all those beautiful buildings destroyed to make way for skyscrapers and bland office buildings...