Across the river from the King William District stands one of the oldest businesses in San Antonio. Founded in the late 1850s by Carl H. Guenther, the mills have remained in operation. The present complex consists of the reinforced-concrete and brick mill building and the towering grain elevator that was added in 1922. The grain elevator is the most distinctive element, with its castellated tower, perhaps recalling the image of a Rhine castle for the Guenther family, who still run the company.