Trier

Germany's oldest city lies at the head of the scenic Mosel Valley, near the border with Luxembourg. An ancient Roman capital, Trier brags that it was inhabited by Celts for 1,300 years before Rome even existed. Today, Trier is thriving and feels very young. A short stop here offers you a look at Germany's oldest Christian church, one of its most enjoyable market squares, and its best Roman ruins.