A UNESCO World Heritage Site, Portugal’s Douro Valley is the world’s oldest wine region, spanning more than 600,000 acres. Its slopes have been carved into hundreds of horizontal steps, each planted with ancient grape vines, which gives the valley its unique patchwork of stripes, curves and textures. Looking out over the rolling hills as they disappear into the gleaming river below is like looking at a piece of art: the more you look, the more detail you see. The valley in northern Portugal has been a Port-producing region for the past 2,000 years, and continues to make some of the highest-quality wine you can find on the planet.