What a strange strange place, i can't make head nor tail of this jumble of boulder.
I spent over an hour wandering around scratching my head, hmmming and arrring.
I'm no ancient fort expert, which would have been evident had you been there with me, still scratching my head now.
Great place for a fort though, if that's what it was.
*Scratches head some more*
"A small promontory fort is formed by a stoney bank and shallow ditch, with rough walls round the other approaches formed by aligning rocks on the site along natural breaks of the slope. A D=shaped area, 15m by 16m, abuts on the inside of the bank within the vestiges of a rough wall. Incorporated in this wall is a long stone of triangular section, on which a pair of opposing slots have been cut in adjacent sides." YAJ 49, 1977