Which small wine region is located on the North bank of the Rhine River?

The Rhinegau is indeed the correct answer because it is a small yet significant wine region situated on the northern bank of the Rhine River in Germany. This area is renowned for its production of high-quality white wines, especially Riesling, which thrives in the region's unique climate and soil conditions. The Rhinegau benefits from the moderating influence of the river, which helps to create an optimal environment for viticulture.

In contrast, Bordeaux is a famous wine region located in southwestern France, known for its red wines, particularly blends from Cabernet Sauvignon and Merlot. Champagne refers to a distinct sparkling wine region in northeastern France, famous for its method of producing bubbly wine, primarily from Pinot Noir, Pinot Meunier, and Chardonnay grapes. The Barossa Valley is an Australian wine region known for robust red wines, particularly Shiraz, and is situated in a completely different geographical context, far from the Rhine River. Thus, these other regions do not pertain to the specific geographic query about the North bank of the Rhine.