Locals were a good help directing me to this, continue up the unpaved track just beyond the yard full of old vehicles, take the gate to the left and continue all the way to the end of the field, the portal is just about visible, almost hidden in the gorse, looks like it hadn’t been visited in a long time, cleared a path around the tomb
Exact location
52.25.44.3 N 06.38.12.7 W