Excellent pics, I really wonder if the marks are / were bomb craters. Have you noticed how the one on the edge of the plantation shows in 1970, and the later pic shows the plantation growing around it !
I wandered around there, there are some curious bits of agriculture, and some MoD looking gateposts, but not much else.
I did reply to diggindeeper, quoted below:
I've looked around the Brimstage site, and there is naff all left. The access road is from Brimstage, fairly obviously, the buildings were at the end of the trackway, there are some bricks - and - that's about it !
The only mention I have is quotes (from "Wirral on the Home Front" book) is:Operating from at least april 1941 (as were most, and all out use by 1943 !), when the Boys Club Hall was acquired by "colonel turners department" to sept 1941, when it was released.
The site was 1/2 mile NW, and knows as "defense works". included a brick built shelter (air raid ?), nissen hut, and an underground building housing an engine (sounds like a standard bunker / generator), trenches and a roadway. Every farm put in claims for bomb damage (nothing changes ?), but most were craters caused by falling AAa shells (what goes up - comes down).
Even the 1970's cheshire cc aerial photos show nothing much, but the OS map does show a building. brimstage
All the standard bunker types are on: decoys
The Storeton AA site is fascinating, it seems to have started with 2 guns, and expanded to 4, but the accomodation appears to have outgrown everything (the arrow shaped bit going to the top right). Often extra acconmodation was required if there were women on site - many AA sites were manned by women - and they had lined Nissen huts - and curtains !
It may be explained because the accommodation often served local sites, ie Brimstage decoy, and the Storeton radar.
All in all, the brimstage area was busy, and also mysterious, because 2 installations, the AA and the radar, seemed to last well beyond the end of the war. Also the mysterious "copses" appeared from nowhere - although the Stallinborough aa site has been deliberately planted in a similar manner with trees !
I had a look around the copse a few weeks ago, I think the depressed bit may be the sewerage pit.
On the same day, I had a look at the Raby (Neston) aa site, and was surprised to find the accommodation huts still extant, and still being used as farm buildings. nice touch.
Sorry to go on, but I'm working at home today.
It's worth a good look around the Sutton Weaver site, Puddington is closer, but I've never felt safe, or welcome there !