A steel mono tower that had a 20kw turbine on it with 30' blades. It is still on its foundation. I have the steel foundation ring and those 4' bolts that are about $100 each if bought here. 24 of them.
Have engineered plans for the foundation approved in Butte County.
One day with a crane to take it down.
Could be for cell tower- consider renting it to a cell company if you are in a good location. It also makes a good osprey nest. They went somewhere else this year.