It appears to be an I-beam (portion thereof) with a reinforcing web at one end. Perhaps it once held a festoon trolley, or other suspending/hoisting mechanism.
It looks to me like the bottom (buried) part of a steel fence post for a wire fence. Was it in the ground vertically? Someone could have been lazy when then pulled the fence out and only cut off the post at or just below ground level.
They cut an I-beam because they were feeling lazy!?!?
It’s too big to be a Ford I-beam (#9 in the link.) It isn’t bent either. All the same, it’s not just a run of the mill I-beam; it tapers towards the bottom, and it looks like the top is boxed or the web is thickened with a hole in the end for a bolt or pin.