Helsbury Castle or Beacon is a fine circular earthwork. Looks like it could be Iron Age.
It has a square ruin in the centre said to be the remains of a medieval chapel.
The site is 684 feet above the sea and is sometimes called St. Syth’s beacon.
The chapel must be pretty old as it was in already in ruins when William of Worcester visited it in1478.
It reminds me very much of Knowlton Henge in Dorset which also has a religious building plonked in the middle.
themodernantiquarian.com/browse.php?site_id=44#post-2117
Great views of Roughtor to the north-east.