Grouse butts vary greatly in their construction; generally they are built on open moorland as individual structures but it's not uncommon for them to be built along a wall such as here. The line of butts is named - Howside Wall - and numbered, the nearest being number one. The turf topping to the wall at the butt is presumably to prevent damage to expensive shotguns rested there.
Uploaded to Geograph by Trevor Littlewood on 11 December 2013
Photo © Trevor Littlewood, 11 December 2013. Licensed for reuse under this Creative Commons licence