Please help as I dont know whether to fill it back in or do something with it or call the water board?!
I tried to upload photo but it is too big so i will describe the hole.
Oblong opening but mostly round hole in the ground to the side of a garden path. The hole is wider at the top and gradually narrows to around 2/3 of the size at the opening (Opening is around 40cm diameter). It is entirely lined with some sort of cement (not modern kind). Thickness of the cement walls is about 5cm; depth of the hole is around 60-70cm. At the bottom of the hole is a flat circular surface. In the centre is a metal pipe going further downwards into the ground (diameter of the pipe is around 4cm). The pipe contains water and some sandy gravel. The pipe lets in water slowly and continuously so the hole fills with water coming up from the pipe, which appears relatively clean (no smell so not sewage).
Could not get past gravel and stuff filling the pipe, but which still lets water seep up.
What on earth is it?
Also for info my terrace house in kent, was built around 1910.
Please help.
Thanks, Londonclay