This is found by carrying on up the lane from west crowlands to the old abandoned farm-house. Just before the entrance to the farm there is a red gate, open this (its in bad repair so don't climb over) then there is a gap on the left. Go thru the gap and there are some low blackthorn trees on ur right. Enter the field on the other side of them and look across into the field next door you should be able to see the standing stone. From the stone it is easy to find the tomb.
There is very little left of the tomb but it seems to be perched on top of an unusual hill. There are the remains of a bank around it as well but this may be the remains of an old field system.