Trier
Germany's oldest city, Trier sits on the border with France and Luxembourg. Trier was established as a settlement in 2000 BC and by the first century AD, the Romans had made Augusta Treverorum their Western capitol for Great Britain and Gaul. Put on your walking shoes - Trier is a place to discover on foot.
On a nice day plan a walk around the actual ruins of this Roman capitol - they're impressive. Take in the Amphitheatre, Constantine's Basilica, the Imperial Baths, and Roman Bridge.
Start your walk at the Porta Nigra ("black gate") - the remnant of 4 mile long city wall and largest Roman gate in the world.
After your stroll, stop in at the Landesmuseum, which has the best collection of Roman artifacts in Germany - so much that only a small part is on display, from mosaics to glass to gold coins. Even the courtyard is jammed with Roman sarcophagi and columns. (In fact, antiques dealers here will sell you Roman coins!) You'll also see Stone Age and Medieval treasures as well.
The Stadtisches Museum (City Museum) right next to the Porta Nigra, has medieval artifacts, Renaissance paintings, Coptic textiles, Egyptian mummy portraits, original stone work of the Market Fountain and the Market Cross. Don't miss large model of Trier circa 1800, where you'll see a video showing how the city developed from Roman times.
The Spielzeugmuseum (Toy Museum) on Nagelstrasse is definitely worth a stop - Germans have always been wonderful toy makers and you'll see some of the best here: a big collection of mechanical toys, trains, dolls, tin soldiers, and stuffed animals.
The Market Square is really very pretty, with a 400 year old Market Fountain showing St. Peter surrounded by the virtues of Justice, Strength, Temperance, and Wisdom - and a few playful monkeys! The obelisk in the center, the "Market Cross," is a copy of the original (in the Municipal Museum) put up in 938 after a Viking raid. You'll also want to see the beautiful Catholic St. Gangolf's Church as well. This is a great central place for lunch or a snack while you're changing gears on your Trier trek.
The Judengasse (Jews' Alley) - Jews settled in Trier in the first century A.D. and this alley leads you through the medieval Jewish Quarter where the cellars of four Jewish houses built in the 13th century survive. Although today's Jewish community is quite small, they do have a New Synagogue on Kaiserstrasse.
Just outside Trier, you'll find the Open Air Museum dedicated to the folk culture of this spot where Germany, France, and Luxembourg meet. Kids will like the walk-through exhibits of everything from a blacksmith, wine and brandy production, a wheat mill, how linen is made, and can even watch semi-precious stones being smoothed.
Stroll down to the Zurlauben (water front) and take a boat ride from Trier to the village of Pfalzel, once the site of a Roman palace (you can still see the marble and mosaic floors) it's one of the prettiest villages in Germany.