Walking Tours -- The Luxembourg City Tourist Office has an excellent brochure entitled A Walk Through the Green Heart of Europe to self-guide you through town. The tour can be covered in 1 to 2 1/2 hours, depending on your route and how long you choose to tarry.
Train Tours -- One of the city's best tours is on the Pétrusse Express (tel. 26-65-11; www.sightseeing.lu), a petit train touristique, a brightly painted "little tourist train" on rubber wheels that takes the weight off your feet when you tour the city. Don't worry: You don't need to be a "little tourist" to step aboard. The train departs twice each hour from place de la Constitution and travels paved pathways through the Pétrusse and Alzette valleys, and on through some of the oldest sections of town to one of the original city gates. Simply sit back and enjoy the passing scenery, or don earphones and listen to a historical commentary (in English, among other languages). The train runs from mid-March to October daily every 30 minutes from 10am to 6pm. The 50-minute ride is 8.50€ ($14) for adults, 5€ ($8) for children ages 4 to 15, free for children 3 and under, and 27€ ($43) for families.
Bus Tours -- The Hop On Hop Off (tel. 26-65-11; www.sightseeing.lu) circular bus tour, onboard open-top double-deck buses, brings you to the cathedral, the grand duke's palace, the remains of the fortress, the European Center, and some of Luxembourg's most important avenues. The buses operate from the last week in March to October daily, with departures every 30 minutes between 10am and 5pm from place de la Constitution. The fare is 14€ ($22) for adults, 11€ ($18) for seniors and students, 7€ ($11) for children ages 4 to 15, free for children 3 and under, and 35€ ($56) for families.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.