Terrible mountains is what Leonardo da Vinci called the peaks that surround the Valtellina. They take the leading role in this story, which is rendered with the help of spectacular film footage and the stories of local inhabitants. With its dry stone walls – a masterpiece that has been declared a World Heritage Site by UNESCO – Valtellina is a land of traditions, contrasts and breathtaking landscapes. From the Stelvio National Park, with its imposing Forni glacier, to the peat bog of Pian Gembro, and from the mysterious crotti of Chiavenna to the terraced vineyards on the Rhaetian slope. In an attentive and intimate way, the film takes the audience on a journey along the river Adda that crosses the entire valley. It begins in winter until the following autumn according to the infinite cycle of nature, which is a stern but honest friend of the people living in this land located in the far north of Italy.