3 Best Sights in The Luxembourg Ardennes, Luxembourg

The reservoir was dammed in 1961 to create a long-term source of drinking water for Luxembourg. Chunks of it are still off-limits because of this, but there's plenty to explore. In summer, solar-powered boats (May–October) take you on two-hour tours of the water. Mercifully, no motorboats are allowed here, but on warm days the lake fills with windsurfers, paddlers, and wild swimmers. You can rent canoes, kayaks, and SUPs from the youth hostel in Lultzhausen in July and August, and for walkers, there are some 90 km (56 miles) of trails to explore (maps are at the visitor center). But if you'd rather relax, several beaches line the shores at Insenborn, Lultzhausen, and across the water at Liefrange, with a more secluded stretch found just past the Burfelt viewing platform. This is where locals come to escape for the day. 

Building began on the castle around 927 AD and it later passed down through the Counts of Esch, who gradually expanded its fortifications. At one point their kingdom stretched to Diekirch, but by 1330 their light had been extinguished, with many of their number lost to the Crusades. Today, visitors can scrabble the two main sections left standing, including what remains of the original keep and the 15th-century round watchtower. 

Between Stolzembourg and Vianden stretches a pretty promenade. This 8.5-km (5-mile) boardwalk trail parades the edge of the lower basin of the river north of town, away from the road. It's a breathtaking stroll and not too difficult to walk or cycle. It takes around two hours to complete, and if you want, you can always get the No. 570 bus back. Its starting point is opposite the Tourist Information Office.