The VI O'Higgins Region is one of Chile's 15 first order administrative divisions. It is subdivided into three provinces. It is named in honour of Bernardo O'Higgins Riquelme, one of Chile's founding fathers. The O'Higgins Region is bordered to the west by the Pacific Ocean, to the east by the Republic of Argentina, to the north by the Valparaíso and Santiago Metropolitan Regions, and to the south by the Maule Region. The capital and largest city of the region is Rancagua. The second major town is San Fernando. In pre-Quaternary times extensive Nothofagus forests covered much of O'Higgins Region.