Built by Greenwell of lava rock and of ohia posts and beams, this structure originally housed a store and post office, both of which he operated. It is the oldest commercial building to survive in the Kona district. Born in England, Greenwell came to Hawaii by way of Australia and the California gold fields, arriving in Kona in 1850 as a representative of Mr. Holdsworth of Honolulu, an importer of British merchandise. During the 1880s, he expanded his endeavors to include dairy farming and, later, ranching. For a number of years the store served as a ranch store and warehouse prior to being turned over to the Kona Historical Society in 1978. Today the building operates as the society's headquarters and museum.