Casona Ochagavía, Historical Monument in Pedro Aguirre Cerda, Chile

Casona Ochagavía is the manor house of the former Ochagavía estate in Pedro Aguirre Cerda, Santiago. Built between 1760 and 1770, it served as the seat of the Chacra Ochagavía, whose lands covered much of today's commune. From 1993 it housed the municipal offices until the 2010 earthquake, after which a new building was added on the south side of the grounds.

The manor was built between 1760 and 1770 and later served as a strategic base for the patriot army before the Battle of Maipú in 1818. It played an important role in Chile's independence campaign.

The building shows the traditional construction methods of 19th-century Chilean manor houses with walls made from clay and straw mixtures. The architecture reveals the everyday living spaces of a wealthy family from that era.

The property is managed today by the municipality of Pedro Aguirre Cerda and remains accessible to visitors. Extensive restoration work was completed following the 2010 earthquake to preserve the building.

The tree from which José de San Martín watched the royalist army at the Casona de Lo Espejo in 1818 stood on this land; the sources do not identify its species, and no eucalyptus is mentioned. The estate also gave its name to the Acción de Ochagavía of 1829, a battle of the civil war fought here.