Winzer Krems is the big cooperative winery on Sandgrube 13, drawing grapes from many growers around Krems and the eastern Wachau. It is not a tiny romantic cellar; it is a useful place to understand the scale and quality of the region's wine production.
The visitor route explains Wachau and Kremstal wine in a clear, accessible way, with tastings of Grüner Veltliner, Riesling, and other local bottles. If you want to buy wine before heading back to Vienna, this is one of the easiest places to do it properly.