It'd be really neat if that post was still around in the same location.
this iron one in Delhi, India has stood like this, and is corrosion resistant, since around 400 a.d. and was dented by a cannonball in the late 18c. Still there, still hasn't rusted away, tho their is some surface rust in places...
https://en.wikipedia.org/wiki/Iron_pillar_of_Delhi