The lime kilns ...

... at Shellbraes Farm.  This is an interesting guide to such structures across the county - Northumberland Limekilns:
The demand for lime to improve agriculture in Britain rose rapidly in the eighteenth and into the nineteenth century. In areas where limestone was found there developed a local industry with field kilns supplying the surrounding area within a few miles carting distance. In Northumberland there also developed a coastal trade with ships carrying burned lime to a range of destinations from larger banks of kilns situated at suitable harbours. With the coming of the railways many of the earlier kilns were closed down as it became economic to produce lime at large commercial units which supplied whole regions.


And, playing on Radio Sandhoe today: Bruce Hornsby - The way it is