There is no fence line

I could measure the width and the length of this block of land. These lines can be very exact and they define boundaries. There is a street to the south with its gutters and footpath. There is a neighbour to the east and the boundary is marked by a row of lilly pillys (Acmena smithii). On the western side there is another neighbour. Along this boundary there is a fence, a now old paling fence. To the north the final neighbour, behind a reinforced wall. But for all these boundaries there is in fact no real fence line according to everything else that lives in or visits this garden.