These big termite mounds--many huger than this one, which is already three or four times as tall as a human (we should have done the classic photo-op thing and had one of us go over and stand next to it)--are everywhere in Kakadu and nearby.  We photographed a taller one, but by no means the tallest one we saw.  They're so resilient that they withstand the monsoons of the wet season.  They're essential to the entire ecosystem of the region.  There are whole books about them; I own one of those.