There was a total of nearly $2 billion of ranches, farms, hunting land and other rural land and acreage for sale in San Diego County recently on Land.com. The total acreage of all San Diego County land for sale was around 100,000 acres. San Diego County ranks fifth out of 58 counties in the state for the combined amount of land currently advertised for sale. There were two properties listed as sold in San Diego County through the Land Network Comparable Sales Program. This represented a total value of $642,800. Of all locations in San Diego County with farms, ranches, and rural real estate for sale, Fallbrook featured the most land for sale. San Diego County is one of the ten biggest counties in California (4,525 square miles). It's located in the San Diego County California region of the state.