KELHEIM, Germany -- Nestled at the confluence of the Danube and the Altmuehl rivers, Kelheim can trace its occupation back to the Stone Age. Caves in the area have yielded dozens of prehistoric finds, including a 50,000-year-old human skeleton. Relics from the earliest cave-dwelling inhabitants through the 19th century can be viewed in the city's small but outstanding Archaeological Museum."Kelheim" purportedly means home of the Celts, and a large portion of the museum features displays from the time when the second largest Celtic settlement in Bavaria thrived on a nearby hill.A portion of the wall which encircled the settlement and ran nearly 10 kilometers still stands in the museum's courtyard. Other exhibits trace the town's history from the Roman period through the 19th century.Like most Bavarian towns, simply walking down the street is akin to visiting a museum. Kelheim abounds in historical buildings, from the many medieval towers that once guarded the walls to the gorgeously situated Befreiungshalle, or Liberator's Hall.Perched high above the Danube, this classically inspired structure was begun by King Ludwig I as a tribute to the champions of Germany who helped to free Europe from Napoleon's grip. It houses an equally impressive collection of sculptures commemorating the 34 states which constituted the German Federation.Rollin' on the river Just outside the city gates, near the so-called "Roman tower," lies the dock where travelers can board a boat for a leisurely cruise along the Danube, the second longest river in Europe. Sail past stunning scenery with such colorfully named formations as "Napoleon's suitcase," "The cave of the Pirates" and "The Petrified Virgin."Take note along the way of an old hermitage housing a church built in a cave with surviving 15th century frescoes. For a closer view, opt to hike along the well-maintained trail following the river, first blazoned by horses hauling barges of salt upriver.The ship continues through "The Gorge," the narrowest and deepest part of the Bavarian Danube. Keep your eyes peeled for some of the 65 iron rings fastened to "The Long Wall." In past centuries, boatmen would use long hooks to grasp the rings and drag their craft upstream.The 30-minute cruise ends at Weltenburg Abbey, founded in 607 and claiming title to the world's oldest monastic brewery. The abbey still houses 14 monks who continue to perform religious services for the surrounding communities.Beer as a religious experience While at the abbey, be sure to step inside the Church of St. George, constructed by the world-renowned Asam brothers in the early 1700s and recognized as one of the most important representations of German late Baroque architecture in the country.Look for images of the brothers themselves who skillfully added their own likenesses within the decorations. For a hint, check out brother Cosmas Asam's visage on the label of the abbey's "Asam Bock" beer.The abbey specializes in nine styles of beer, perhaps the most famous being the "Barock Dunkel," twice winner of the "Best Dark Beer" at the World Beer Awards. Settle down under the shade of the chestnut trees scattered throughout the courtyard/beer garden and enjoy a hearty brew while dining on the abbey's traditional Bavarian fare, including cheese crafted on the premises.Ships run roughly every 30 minutes and a round trip ride costs about eight euros for adults. Entrance to the abbey and the Church of St. George are free. Refreshments are also available on board.With a wide variety of activities in a gorgeous setting, Kelheim makes a great day trip that you'll want to return to again and again.