Rancagua () is a city and commune in central Chile and part of the Rancagua conurbation. It is the capital of the Cachapoal Province and of the O'Higgins Region, located south of the national capital of Santiago. It was originally named Santa Cruz de Triana by Spanish colonists. In 2012, its population was 232,211. The main economic activities range from mining, tourism, agriculture, timber, food production and services to minor industrial activities. The city also serves as the administrative and legal center of the region. Together with Machalí and Gultro, it forms the Rancagua conurbation. After Curicó, Talca and Concepción, it is one of the most important and densely populated cities of the south central zone of Chile. History Foundation period The Rancagua Valley was occupied by the local Picunche. They fell briefly under the control of the Inca Empire in the 15th century. Its remains in structures can still be found near the city today. Through their civil engineering, the Inca accomplished expeditions to the south of their empire. Rancagua was founded by Spanish explorer José Antonio Manso de Velasco, who founded several cities in the central area of Chile. The settlement was first called Villa Santa Cruz de Triana. The city is notable in Chilean history as the scene of the Disaster of Rancagua of 1814, when Chilean forces fighting for independence from Spain were defeated. This marked the beginning of the period known as the Reconquista (Reconquest), an attempt by Spain to regain control of Chile. Today In recent years the city has become one of the most attractive cultural and tourist centers in the O'Higgins Region, largely because of the vineyards that have been developed in the area. Rancagua also offers sports centers and easy access to smaller villages and towns. Other visitors are attracted to the archeological sites, such as Pukara de La Compañia and the nearby Rio Cipreses nature reserve. Both can be visited by private vehicle or with local tour companies. The city is connected to the capital, Santiago, by the Panamerican Highway (Chile Route 5). In addition, the Metrotren connects the metro service in Santiago to Rancagua by train. Rancagua is home of the University of Rancagua (in Spanish), the first private university to be established in the O'Higgins Region. The region is known for El Teniente in the nearby Andes mountain range: it is the "largest underground copper mine in the