The subject of much speculation and, frankly, little fact this looks like a classic hill fort to us, check out the below elevation map of the area with the hillfort showing up beautifully. We have also included elevation profiles so you, dear readers, can appreciate the classic hill top location: note how from all directions the hillfort perches nicely on the top of the highest point: visible from all directions and can see in all directions. A classic see & be seen location, achieving the twin aims of defence and impressing visitors.
One can only speculate the effect the arrival of the roman fort across the valley (also seen in the 1885 map) had on the occupants.
Text and images supplied with thanks by YAAMAPPING