Well, what a surprise this was!
The homeowner has been in residence for a few years and employed our services to undertake an inspection to determine the cause of dampness within some of the ground floor rooms.
Having established the cause, (damp concrete oversite and the absence of a damp proof course), our inspection led us to undertake sub floor inspections in each of the ground floor rooms.
To our, and the homeowner’ , surprise we found a disused well within the sub floor void beneath the Sitting Room floor!
At the time of writing I believe the homeowner is contemplating making a feature of it and this, together with the fact that we were able to propose a resolution to the damp issues, means that ‘All’s well that ends well’. (I’ll get my hat and coat).