Hey guys,
Can anyone help me out here, I went for a bit of a drive this after noon, with a mate and hit a sign on the side of the track that says "private property keep out"

Co ordinates are 33°17.864'S, 151°18.096'E

How can I tell if there claim that is private land is legit, and two I thought there was a law where you had to allow access?

Anyone got any info on this? Or where I could find out if that is indeed private land?