Flower Question

I know this is the RSPB but can I ask a plant question he he

Saw a yellow flowered plant near the path that's sort of on the other side of the reed beds to the centre and not knowing much about flowers I've tried to look it up and it looks most like Wild Cabbage.  However from what I can see this is not supposed to be as far north as this, so could this be what it is or is it likely to be something else?