Trier is the oldest town in Germany. It was originally founded by celts in 4th century BC, but later in the 1st century became a major outpost of the Roman Empire known as Augustus Treverorum. The city has my one but three UNESCO World Heritage Sites – ancient Porta Nigra (the best preserved Roman city gate above the Alps), beautiful Trier Cathedral dating back to the 12th century, and the Liebfrauenkirche (German for Church of Our dear Lady) (an ornate gothic church). But beyond the churches and Roman monuments, Trier is just fantastic to roam around wide squares with beautiful historic houses and coffee shops. Trier is also the birthplace of Karl Marx, and the museum dedicated to him is very popular with Chinese tourists.