This field, with its views to the Black Mountains, is on one of my family’s favourite Sunday afternoon walks. It is always known to us as the blackberry field - I can only assume that we had a successful blackberrying expedition at some point in the distant past, but the defining feature now seems to be thistles. It was also the location for numerous sledging attempts, which were largely unsuccessful due to the distinct lack of gradient.
You are looking for a small bison tube, concealed within something else, at one of the entrance points to the field. You’ll need to bring a pen.
If you’re coming by car, there’s not really space to park at the bottom of Orchard Lane without blocking entrances. I suggest you park further off and walk down, or come in lower down the field along one of the other footpaths.