Wine or the Romans? Which made Trier what it is today? The answer is—both. As early as 30 BC, the Romans introduced viticulture to the region during their occupation and the result has been phenomenal. Visitors can see evidence of the Romans' stay by visiting the Porta Nigra, the best-preserved Roman city gate north of the Alps; the impressive Roman amphitheater; Roman baths; and the Roman Bridge, the oldest bridge in Germany. Other worthwhile sights include the imposing cathedral and the Electoral Palace, which was once the residence of the prince-electors of Trier. Afterward, it's time to relax with—what else? A glass of excellent Moselle Valley wine, courtesy of the Romans!