In reply to aln:
I always thought the hills above Lochwinnoch and Kilbirnie were flat and boring so we ended up looking at the old plane crashes on them.
Hills just to the south had more shape to them. Irish Law, Crosbie Hill and Kaim Hill.
Crosbie Hill has two ring cairns, I think one of them is very old. There are broken millstones on the west side of Kaim Hill.
There was an old pillbox near the road on Green Hill (south west of Kaim Hill).