Trier is full of monuments worth seeing. Often overlooked is the town square just up the street from the Porta Nigra. This square turns into a wonderful Christmas Market during December with some of the best food in the country. The town square is also a street or two from St. Peter's Cathedral which is a great example of Romansque architecture. It houses the holy tunic of Christ. I enjoyed the city immensely. If you want to have a walk that you will enjoy, walk through the Kaiserthermen (Roman Baths) or the Ampitheater. Remember the Ampitheater goes down under as well.