The Douro River Valley, carved dramatically through Portugal's mountainous interior, stands as one of the world's most spectacular and historically significant wine regions, stretching from the Spanish border to the city of Porto and encompassing three distinct sub-regions: the Baixo Corgo (Lower Corgo), Cima Corgo (Upper Corgo), and Douro Superior, each with increasingly arid conditions and different grape-growing characteristics. This ancient wine region, officially demarcated in 1756 as the world's first appellation system, is globally renowned as the birthplace of Port wine, where grapes are grown on vertiginous terraced vineyards carved into schist slopes and then fortified with grape brandy to create the legendary sweet wines that built international trade relationships and defined luxury drinking for centuries. Beyond Port, the modern Douro has revolutionized Portugal's wine reputation through exceptional dry red wines made from indigenous varieties like Touriga Nacional, Touriga Franca, and Tinta Roriz, proving that this challenging terrain can produce world-class table wines that rival the best from Bordeaux or Napa Valley. The region's impact extends far beyond its wines—the Douro's innovative agricultural engineering, with its iconic stone terraces (socalcos) that prevent erosion while maximizing sun exposure, earned UNESCO World Heritage status and serves as a model for sustainable viticulture in extreme terrain. Today, the Douro represents the perfect synthesis of tradition and innovation, where centuries-old Port houses work alongside pioneering producers creating cutting-edge dry wines, collectively establishing Portugal as one of the world's most exciting and authentic wine destinations while preserving cultural practices that connect modern winemaking to its ancient roots.