If it is a concern to you then make sure if/when you make an offer, you make it contingent on review of a survey report or contingent on acceptable survey. You could also visit the municipality building/planning/zoning department for information on property lines.
make sure it was 13 acres and not 13 acres +/-. When you see more or less or (+/-) it means the property was never surveyed. You could be getting much more or less land than you expect when a survey is finally done.