Top-quality Riesling grapes thrive here. Even before the term "terroir" became fashionable among wine connoisseurs, the vintners here were aware of the importance of climate, location, and soil. The latter's mineral composition varies, so that wine tastes are strongly influenced by even small difference in location. The Romans brought wine cultivation to the Mosel more than 2000 years ago. In Trier, the Porta Nigra, a black, weathered, stone gate to the city, still testifies to the Roman-era. In the state museum, the grave of a Roman wine dealer shows that Mosel wine was already in demand in ancient times. Today visitors from all over the world come to the wine festivals here, especially in the autumn, to pay homage to Bacchus, the god of wine. In Piesport's "Roman wine-pressing festival", Bacchus makes a personal appearance every year.