Lindoso sits in the remote northwest corner of Portugal, inside the boundaries of the Peneda-Geres National Park, the country's only national park. The castle occupies a hilltop overlooking the village, the valley of the Lima River, and the mountains of Spanish Galicia beyond. Afonso III ordered it built as part of a broader effort to strengthen Portugal's defensive borders, and its position was well chosen. From the battlements, the view extends deep into both countries, making surprise approach nearly impossible. For centuries, this was frontier territory in the fullest sense, a place where the line between Portugal and Spain was drawn not on paper but in stone.

The castle spent its early centuries in relative obscurity. That changed during the Portuguese Restoration War, which began in 1640 when Portugal broke free from sixty years of Spanish rule. Suddenly, Lindoso's border position made it strategically vital. In September 1641, the castle served as a staging base for Portuguese incursions into Galicia. As the war dragged on, the fortress received extensive modernization, completed around 1666, a date still inscribed on the lintel of one of its doors. The improvements came just in time: Spanish troops briefly captured the castle, only to lose it again three years later. A main ravelin defending the principal entrance was completed by 1720, and the castle saw its last military action during the Napoleonic Wars, when it was placed on defensive footing but never attacked.

The espigueiros clustered below the castle walls are Lindoso's most distinctive feature. Numbering sixty-seven, they constitute the largest and best-preserved collection of communal granaries in the Peneda-Geres region. Each one is a narrow rectangular box of granite, raised on stone legs to allow air circulation and prevent moisture and vermin from reaching the maize stored inside. Slots in the side walls let wind pass through for drying. The crosses at their peaks are not merely decorative; they reflect a rural Catholic tradition of blessing the harvest and the structures that protected it. Seen together from a distance, the granaries resemble a miniature city, their peaked forms echoing the castle towers above them.

After the wars ended, peacetime was not kind to the castle. Without a military purpose, maintenance ceased. Rain, wind, and neglect wore at the masonry for over a century. The Castle of Lindoso was declared a National Monument on June 23, 1910, but meaningful restoration did not begin until 1979. Today the keep still stands, divided into two floors, and the stone walls retain their battlements. The structure is built entirely of stone masonry, with the north and south ends of the tower once accessible by drawbridge. Visitors who climb to the top find a panorama that explains everything about why the castle was placed here: the green valley of the Lima, the granite peaks of Peneda-Geres, and to the east, the mountains of Spain.