The German winegrowing region of Franconia used to be divided into the three areas of Maindreieck, Mainviereck and Steigerwald with 23 major sites and 216 individual sites. In November 2011, the members of the Franconian Winegrowers' Association adopted a new regulation. The three old areas will be replaced by 12 much smaller ones. These will also replace the 23 large sites in the medium to long term. The old areas once played a role in the predominant marketing of Franconian table wine, which they had lost for some time. Before this conversion, the following description applied to the Mainviereck area:
The very small Mainviereck area is located in the west and comprises only about 330 hectares of vineyards. It is named after the landscape formed by the sweeping course of the Main in the form of a quadrilateral open to the north with the municipalities of Gemünden, Wertheim, Miltenberg and Aschaffenburg forming the cornerstones. Here, primary rock soils with mica slate, quartzite and gneiss predominate. The most common varieties are Müller-Thurgau, Riesling, Silvaner and Bacchus. The area is divided into two major sites, Heiligenthal and Reuschberg.