I was alerted to this hill forts existence and whereabouts by TMA contributor Blossom, nice one. Seeing as it is near the road and halfway between two stones on the list, I had to stop and take look, be rude not to.
About five minutes north east from Aberdaron, easily spotted from the B4413. I parked up a small rough farm track that leads to some farm buildings but not the farmers house. Apart from over easily freaked young cows we had the place to ourselves. From the farm barn it is only a ten minute walk up to the top. Marked by a trig point and mapped as 146m high, the top is a wonderful place to be. The whole Lleyn peninsula can be seen from up here, excepting the highest hill tops which are still shrouded in early morning mists. The mists are almost low enough to engulf me on this hill top, they're wafting around just above head height and lending a most ethereal light upon the whole scene.
The hill fort itself isn't that grand or impressive, the ditches aren't deep nor the ramparts high, but they do have a vache-de-frise. A chevaux-de-frise, is a defensive system that has usually sharp things getting in the way of cavalry, as seen at Pen y Gaer and Cademuir hill, but here they have live cows encrusting the ramparts, a bit blunt mostly, but, get through that ya b****rds.
No sign of Odo though, if you go to somewhere that's called castle Odo and there's no Star trekian shape shifters to be seen at all it must be against the trade descriptions act or something, some American tourists might sue.
Perhaps the trig point has obscured the mound within the fort and I could see no sign of any mounding on the outside either, as with many if not all hill forts it's the sighting of the fort, the terrific views from them that keeps me climbing these places. Odo rests on .
.. on the side of the hill called Mynydd Moelvre, or Mynydd yr Ystum, are the ruins of an old chapel called Capel Odo; and near it tumulus distinguished by the appellation of Bedd Odo or Odo's grave, who according to tradition was a great giant.
The aerial photos on Coflein's record for this site show the double bank clearly, so Odo's castle is still there. They don't mention the remains of any chapel. Their record for the mound within the fort suggests it's of medieval or later origin, maybe a pillow mound for rabbits. Perhaps that's the mound that's Odo's grave?
Perhaps wholly unrelated, but certainly very close by and directly east of the fort is Ffynnon Ddwrdan, a holy well on the Afon Daron.
Quote from 'The History of North Wales' v2, by William Cathrall (1828).