NHER 24988 (Monument record) - World War Two defensive position

Defensive position?
Ditch approximately 3m wide and 1.2m feet deep forming circle, with regularly spaced causeways. Inner embankment about 1.2m high with gap opposite southern causeway. Nissen hut in centre. On former heath, now wooded, trees grow from bank as well. Grid reference may not be entirely accurate owing to change in land use. Presumably World War Two defensive position. Similar earthworks without the hut have been noted elsewhere in the county but not previously explained.
E. Rose (NAU) 5 January 1989.

October 1995.
Site has apparently been destroyed for the making of a new turning area for forestry lorries.
E. Rose (NLA) 3 October 1995.

See (S1), which also show a second similar feature a short distance to the north.
Gun emplacement or searchlight battery? Adjacent to bombing range?
D. Gurney (NLA) 14 December 1995.

January 2000.
Turning area now abandoned; natural regeneration of grass and heather has revealed the site of the hut as a cropmark, though remarkably, not the ditch.
E. Rose (NLA) 14 January 2000.