Established in 1948, Calstone is a provider of concrete masonry and landscaping products in the Northern California region. Based in Sunnyvale, Calif., the company produces paving stones, retaining walls and landscape structures. It offers paving stones in a variety of designs, such as Quarry Stone, Classic Cobble, River Rock and Symetry. In addition, it provides concrete masonry units of various types, such as Fencewall, Precision, Slump, Split Face and Ground Face. Calstone caters to a wide spectrum of sectors, including residential, commercial, industrial and institutional construction.