San Giacomo is a mountain village in the Province of Teramo in the Abruzzo region of Italy. It is a frazione of the comune of Valle Castellana. San Giacomo lies at an altitude of 1105 m, within the Gran Sasso e Monti della Laga National Park. The town takes its name from the presence of an ancient building, belonging to the monastery of San Giacomo, which …San Giacomo is a mountain village in the Province of Teramo in the Abruzzo region of Italy. It is a frazione of the comune of Valle Castellana. San Giacomo lies at an altitude of 1105 m, within the Gran Sasso e Monti della Laga National Park. The town takes its name from the presence of an ancient building, belonging to the monastery of San Giacomo, which once sat at a slightly lower elevation. This building served as a refuge for workers who once tilled the landholdings in the area that belonged to the church. One ridge in this area still carries the name Costa del prevosto in reference to this fact.