The previous owners of our house had the foresight to buy a little triangle of land from the farmer next door. This extends the back garden considerably, but also means that the old wall and hedge serve no useful purpose - instead, they just block the view.
I had already made a small gap in order to be able to access a winter wood pile behind the hedge. Now, it's time to get rid of the hedge and the drystone wall completely. It will be a long job.