1751 Concepción earthquake in the context of Chillán

Concepción (Spanish pronunciation: [konseβˈsjon] ; originally: Concepción de la Madre Santísima de la Luz, "Conception of the Blessed Mother of Light") is a city and commune in south-central Chile, and the geographical and demographic core of the Greater Concepción metropolitan area, it is the second largest city in Chile by urban area and one of the three major conurbations in the country. It has a significant impact on domestic trade being part of the most heavily industrialized region in the country. It is the seat of the Concepción Province and the capital of the Biobío Region. It sits about 500 km south of the nation's capital, Santiago.

The city was first settled in the Bay of Concepción, in the zone that would later become the commune of Penco, now part of the Concepción conurbation. The city's demonym, penquista, comes from the place of its original foundation. The city center and historic district is located in the Valle de la Mocha (La Mocha Valley), where it relocated after serious damage left by an earthquake in 1751.

Valle de la Mocha ("the Valley of Mocha") is a plain in Chile on the north shore of the Bio-Bio River that contained the reducción of Mapuche who were transported in 1685, from Mocha Island by Governor José de Garro; from which the valley and plain took its name. Governor Domingo Ortiz de Rosas transferred the old city of Concepcion to this site from Penco after the May 25, 1751 Concepción earthquake.