Not 100% sure this is a gardening question, but thought I'd start here in case anyone had seen similar
Around November last year after the last cut of the season, this curved line appeared in the grass. At first I thought maybe a cat had walked and left an impression, but after a good few cuts this year, its still there. On closer inspection, its actually sunk below the grass level.
It starts and ends between an old concrete path which goes down about 10 inches and a garden bed, close to a wall and there are no drains or pipes on that side of the garden.
I'm wondering could it be mole tunnel thats collapsed maybe ? just wondered if anyone has seen aything similar