Location & Terroir Vineyard: In 1845 Jodocus Prüm had the now world-famous sundial built on a rock in the Lammerterlay, originally intended as a means of time orientation for the vineyard workers. The location has a south-southwest orientation with a slope of up to 70%. Our Riesling vines are up to 80 years old. Terroir: Stony clay slate weathered soil.