The northern side of this fort needs no bank or ditch because the cliff face drops steeply away towards the river below, making the natural topography an integral part of the design. It is an arrangement that speaks to a particular kind of practical intelligence: why shift earth where stone and water have already done the job for you.

The fort is defined on its eastern and south-eastern sides by three earthen banks with intervening fosses, the term for the ditches between raised defensive banks, before the earthwork system gives way to a single inner bank running south-east to west. The inner bank is substantial, rising roughly one metre on its interior face and nearly three metres on its eastern exterior. Where the outer two banks and their fosses come to an end, a low curving bank bridges the gap, closing off the space between them. The north face of this inner bank is stone-built rather than earthen, dropping steeply to revett, or retain, the ends of the fosses below. A stone drain runs from the base of this stone face into the fosse, and there is evidence that both fosses have been further shaped over time by water action, the river's influence working quietly on the archaeology long after whoever built the place had gone. The interior itself sits raised above the level of the field to the south, which would have given anyone inside a clear view of approaching ground.

The entire site is now heavily overgrown, and a machine-cut drain has been inserted outside the outer bank at some point in the more recent past. The vegetation makes the full geometry of the earthworks difficult to read from ground level, though the logic of the cliff-edge position becomes clear enough when you stand on the northern side and look down.