Union County is in Alleghenies & Valleys Pennsylvania. Of the 67 counties in the Keystone State, 317-square-mile Union County ranks 64th by size. There is about 1,000 acres of residential land for sale in Pennsylvania's Union County based on recent Land Network data, making it the most common type of land for sale in Union County. The combined market value of land for sale here is around $9 million. The average price of residential acreage for sale in Union County was $513,729. Browse all residential land and rural property for sale in Pennsylvania to find residential land and properties that suit your lifestyle needs, from existing residential homes and estates to land ready for future residential-property development.