Vieira de Sousa produces Port wines from the Douro region of Northern Portugal, where the steep schist terraces and continental climate shape the character of traditional fortified styles. The winery draws on the region's classic grape varieties—Touriga Nacional, Touriga Franca, Tinta Roriz, and Tinta Barroca among them—to craft expressions across the Port spectrum. The Quinta da Agua Alta 30 Years Tawny Porto, a blend of Touriga Nacional, Touriga Franca, Tinta Roriz, and Tinta Barroca, represents the oxidative aging tradition central to tawny production. The Ruby Port, built from Touriga Franca, Tinta Roriz, and Tinto Cao, and the Late Bottled Vintage Port—a more complex blend spanning five varieties—demonstrate the winery's range within the fortified category. These wines have been assessed by major critics including Wine Advocate, Wine Spectator, Wine Enthusiast, Decanter, and Falstaff.