Trier is one of Germany’s oldest cities, founded by the Celts in the late 4th century BC. It’s also one of the country’s most beautiful, with a well-preserved old town that’s been designated a Unesco World Heritage Site. The city is home to a wealth of historical attractions, including the Porta Nigra, a 2,000-year-old Roman city gate, and the Imperial Baths, a lavish bathing complex from the days of the Roman Empire. Don’t miss the Dom, Trier’s magnificent cathedral, or the Church of Our Lady, one of the city’s most striking Romanesque churches. Trier is also a great place to sample some of Germany’s best wine, with vineyards stretching out from the city in all directions.