Kloster Weltenburg (Weltenburg Abbey) is a Benedictine monastery on the river Danube near the city of Kelheim in Bavaria. The monastery, founded by Irish or Scottish monks in about 620, is considered to be the oldest monastery in Bavaria. It is also famous for its brewery (Weltenburger Klosterbrauerei). The brewery, in operation since 1050 and famous for its dark beer, is the oldest monastery brewery in the world.
Walking around on foot is by far the easiest method of getting about, and given its size, unless you intend to do some serious hiking or rock-climbing, is the most practical method as well.
Should you feel adventurous, several distinct, 12-person wooden boats with outboard motors operate a for-hire ferry service, and can take you across the Danube to the hiking path (allowing you to walk, bike, or hike), or can even take you all the way back to the nearby village (though you may want to compare the price to the ferry).
The pub in the abbey serves not only beer, but also Bavarian cuisine.
The monastery has a brewery (oldest monastery brewery in the world) and a pub. Weltenburger Kloster Barock Dunkel, the local dark beer, was given the World Beer Award in 2004 as the best Dunkel beer in the world. The beer is strictly brewed to a Bavarian standard of Beer (similar, although not as regionally-restricted, to the classification of "Wine" in France), which can only be made of four ingredients: hops, water, grain, and sometimes yeast. This particular beer has a slightly sweet taste, with a pleaseant aftertaste and a deep, dark colour.