Why not make the gap into a raised flowerbed in a matching deck style?
One focal point for another - even if you are that lazy that looking after a flowerbed fills you with the same horror that a fishpond does, you could do a gravel & posh grass job that needs little love.
That's a great suggestion, thanks!
Reflecting on the current pond, it is a substantial pond as the current owner's business is ponds and pond equipment. It looks more like a small lake to me!
Even the survey commented that there is a 'substantial pond' in the garden that would be a risk to children and small animals.
I'm looking for the path of least resistance to fill it as 'lazy' doesn't even begin to describe me. Naturally i'll be looking into getting professionals in to do the work.