Of 21 counties in the Garden State, Warren County ranks 11th by size (362 square miles). Warren County is in North New Jersey. Recent listings of farms for sale in New Jersey's Warren County totals approximately 1,000 acres and a combined market value of approximately $1 million. The most common type of land for sale by combined acreage in Warren County is house. Browse all Warren County farms for sale on the Land Network to find the farm, cattle operation, hobby farm or other farm property that's right for your future commercial or lifestyle needs. The most common type of land for sale by combined acreage in Warren County is house.