Answer June 2020
The clue image is of the cast iron door on the Sele Well, on the path up from Cockshaw. Apart from the trees and the foliage, it seems little changed from the image from 1906 which is in the Sele Gallery section of the HLHS Photo Archive.
The Well appears on the 1826 Woods Map of Hexham, and according the the Historic England website (link below) dates from at least 1823. The above map extract was from a survey in the 1850s and published in the 1860s.
More information about the well appears in the Historic England web site and also here .
If you have any thoughts or knowledge about the building, please contact us, or use the “Comment” section below.
Thanks to Stefan for the modern images.
When we played on the Sele and needed a drink of water we used this well. The only way to get to it was to go to go end of Seal Terrace and go down the common path or go down the bank at the Sele school.We had to do that as the whole of the common was fenced off.