Small plant with four petaled white flower.
No interactions present.
Looks like a saxifrage to me.
it dosen't look like any in my book and they all seem to have five petals.
Howardian Local Nature Reserve
Oh well it was only a guess.
It looks like a crucifer but has thrown me completely - nearest guess is something like Cardaminopsis arenosa but what would it be doing there?
Lat/Lng: 51.5, -3.2
OS grid ref: ST2079