douro river meandering through vineyards and villages in mesao frio, douro valley, portugal under cloudy sky

douro river valley vineyard vineyards wine region viticulture landscape scenic portugal europe mesao frio vila real hills terraces agriculture grapes nature travel tourism destination picturesque beautiful summer green cultivation rural countryside idyllic serene tranquility calm peaceful vine grapevine winemaking tradition heritage exploration discovery wanderlust view panoramic aerial clouds sky