Termas de Cauquenes, Hot springs complex in Machalí, Chile

Termas de Cauquenes is a thermal complex on the bank of the Cachapoal River in Machalí, 31 km east of Rancagua at 760 m above sea level. Its waters range from 42 to 48 °C and carry bicarbonate, chlorine, lithium, magnesium, oxygen and potassium. A wooden Gothic-inspired hotel built in 1885 is reached by an old wooden bridge; inside is a large Italian-style bath hall with a European marble tub and modern whirlpool baths. An old native forest with endemic and some introduced species stands beside the buildings.

Indigenous Picunches and Promaucaes knew the springs before the Spanish arrived, and chronicles record healing journeys there for over four hundred years. By the mid-17th century large adobe houses stood around the baths, owned by the Jesuits. In 1819 José de San Martín visited to treat his arthrosis after Bernardo O'Higgins wrote to him on 3 May praising the waters. The wooden Gothic-inspired hotel was built in 1885.

The name Cauquenes comes from the indigenous picunches and promaucaes, who knew the springs before the Spanish arrived; chronicles over four hundred years old record healing journeys here from across the country. In 1819 Bernardo O'Higgins wrote to José de San Martín on 3 May praising the waters, and San Martín came to treat his arthrosis. The English traveller Peter Schmidtmeyer later described six baths at 83 to 118 °F and a cold spring beside one of them.

The complex lies 31 km east of Rancagua at 760 m, on the Ruta del Ácido beside the Cachapoal, and is the obligatory way into the Río de Los Cipreses national reserve. Access to the hotel is over an old wooden bridge. The baths sit in native forest, so bring a towel and footwear for wet ground.

The hotel was bought in 1980 by Swiss chef René Acklin, who restored it and turned the springs into a resort; after his death on 5 August 2009 it passed to his daughter Sabine. The 2010 earthquake altered the course of the thermal water, and the operating company was declared bankrupt on 28 December 2010.