Santo Arbol de la Cruz was a fort constructed in 1585 by the Royal Governor of Chile Alonso de Sotomayor. It was located north of the entrance of the Guaqui River into the Bio Bio River near the modern rail station and village of Duiquín. In this site, the Jesuits established a residence, in the settlement of Postahue that was abandoned upon the expulsion of the Jesuits in 1767.