The black slab on the beach at Ayr which is the western end of the River Ayr Walk.

It's not at all apparent but the reason the black slab is at an angle of 78° East/258° West because it points directly to the marker up at Glenbuck at the other end of the River Ayr Path - twenty eight miles away in a straight line.

From closer in you can see that it's made of wooden panels. An information board has now been added.

Looking northwards over the harbour. All of these images were taken just on high tide.