Take Me to the River

Skip the hotel gym the next time you're in continental Europe: head for a jog beside the Danube instead. This khaki-colored river (Johann Strauss must have been either color-blind or in the throes of poetic license when he put "Blue" into the title of his famous waltz) is lined with hiking and jogging trails that make it one of the region's best-kept recreational secrets.

The 2,850 km-long Danube kicks off in Germany's Black Forest and flows eastward through 10 countries to the Black Sea. Once part of the Roman Empire's border against barbarian hordes to the north—and of vital strategic importance to contending armies during the two World Wars—the Danube is now a more lighthearted place. On any given Sunday, whole stretches of it are abuzz with dog walkers and horse riders as well as runners.

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Avoid the sections of the river that run parallel to the noisy, traffic-clogged autobahn, and stick instead with havens like the flat, unpaved trail that skirts the northern edge of Dillingen, a factory town of roughly 18,000 in Germany's southwest. Despite the proximity of urban development (Munich is just a 45-minute drive away), the area is rich in wildlife. Look out for hungry ducks and other fowl dive-bombing a river teeming with fish, plus the occasional huntsman, struggling to get an overexcited dog to heel.

If you prefer hunting down cultural treasures, then call at one of the many historic towns and cities built on the Danube's banks. Budapest, Hungary's capital, is one of the most graceful. The Danube (or Duna in Hungarian) divides the city into the hilly side (Buda) and the flat side (Pest), from which it gets its name. Jog through the former and you can check out the gorgeous 15th century Royal Palace and the 700-year-old Matthias Church. Pick up a trail on the latter for views of the neo-Gothic parliament building and the beautiful Central Market Hall. Can't choose between them? No matter. The three bridges that connect the two sides allow you to zigzag to your heart's content. Afterward, you can soothe your aching muscles with a soak at the city's famous bathhouses. Two top picks are the neo-Roman Gellert Baths and the Lukacs Baths, both on the Buda side of town.

If you enjoy distance running, the Danube's long, flat stretches offer rich opportunities. Among the best-known routes is that of the Linz Marathon, which kicks off every April in the Austrian town famous for its torte (last month's saw over 10,000 competitors take part). Those planning to enter 2006's should start training now. Those not contemplating anything quite as strenuous should get down to the waterway anyway. The fresh air and ever-changing riverscapes will have you waltzing through your workout.