Trier has some of the best Roman ruins outside of Italy. Our family went there in June of this year and had a fabulous time. The Porta Nigra is a Roman gate turned, church, turned into other things and then a tourist attraction. From there we stepped into a carnival of venders, sights from all parts of German history, a cathedral, a palace, two Roman baths, and a huge basilica. This little town couldn’t shove more sights into a smaller area if it tried. If you ever do go visit, pay for a map and every see if you can get your hands on a tourist book. All the these places are walking distance from each other. My one year old son love hobbling all over and trying various types of German junk food and we enjoyed our stroll through history.