Set at the confluence of the Krems and Danube rivers, at the eastern end of the picturesque Wachau Valley, is the intimate town Krem san der Donau. Often encountered on a narrated day of scenic cruising through the valley, the hamlet is most frequently passed while en route to other places of more significant interest. Still, a stop in Krems (as it is locally known) could very well be one of the highlights of any Euro river cruise for access to the vineyards here alone. If you’re sailing by, look for Schönbühel Castle on the south bank between Melk and Krems. It's hard to miss the imposing Aggstein Castle, too.