Armstrong County is in Pittsburgh & Countryside Pennsylvania. Of the 67 counties in the state, Armstrong County is 34th in terms of its size (663 square miles). Armstrong County, Pennsylvania, includes around 1,000 acres of residential land and property for sale based on recent Land Network data. The combined market value of farms, hunting land and other rural land and acreage for sale here was nearly $12 million. The average price of residential land for sale in Armstrong County was $458,640. 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.