A small centre of the Lomellina area, near the Park of Ticino, Alagna is an ancient town in the province of Pavia, located along the riverbank of the stream Terdoppio. The town's name derives, according to some, from the appellative of the early inhabitants, the Alani, a barbarian tribe from the East, that settled here around 500 A.D., according to others, however, it derives from the quotation of Pliny the Elder with reference to a region "Aliana inter Padum Ticinumque amnesia" famous for its linens.
In the Middle Ages, the town belonged to the Malaspina family, who ceded it to the noble Caimi Family, then it passed to the D'Adda Family.
The D'Adda Family coat of arms, appears on a stone frieze on the façade of the Castle of Alagna, dating from the XVI century. At short distance from the castle stands the Parish Church of San Germano, entitled to the patron Saint of the town, completed in the early XII century and stands where a more older church, always dedicated to the same Saint, was situated of probable Romanesque origin.
Interesting are also the remains of a monastery of Vallombrosana origins of the XIV century and a mill of the same period.