Trier is a beautiful city and well worth the visit if you are in the area. It's very popular with tourists since it has a rich Roman history. If you decide to go to Trier, I would suggest a drive along the Mosel river to see some of the beautiul little towns like Bernkastel-Kues, Traben Trarbach and Cochem. One of my favorite places is the city of Luxembourg that i would also recommend to anyone visiting the general area.