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 (Ridge of the Provost) in reference to this fact.