I always thought that before buying land you need a survey first? Someone I know bought land, built a house but some time later when his neighbors turned up and informed him that he'd fenced in part of their land he didn't want to hear any more. He had them kicked out of his house but when the surveyors came they convinced him that his land was much smaller than those who'd sold it to him wanted him to believe. How common are such [boundary] disputes? Do they arise because someone fails to get the property they are buying surveyed or do they deliberately "invade" their neighbors property?