Though it’s not quite in the Cajón del Maipo [1] proper, Viña Santa Rita (Camino Padre Hurtado 0695, Alto Jahuel, tel. 02/3622594, www.santarita.com [2], rrivas [at] santarita [dot] cl) is part of the Maipo drainage, east of Buin and southwest of Pirque.
Bernardo O’Higgins and 120 of his troops hid from the Spaniards in the catacombs at Hacienda Santa Rita, a distinguished winery that named its main line of wines—120—after the event. Today, its main house is a hotel, the former colonial house (a national monument) is a restaurant, and the grounds and cellars (also a national monument) are open for tours (US$9 pp with tasting) five times daily from Tuesday to Friday. On weekends and holidays, tours are free with lunch (which costs around US$35) but do not include sampling the produce.
Santa Rita’s 16-room Hotel Casa Real (tel. 02/8219966, hotelcasareal [at] santarita [dot] cl, US$260–350 s or d) is open by reservation only; its restaurant, La Casa de Doña Paula (tel. 02/3622520) is open 12:30–3:30 p.m. daily, also by reservation.
Buses from Pirque to Buin pass by the front gates. For obligatory reservations, contact them at least a couple days in advance.
Links:
[1] http://www.moon.com/destinations/chile/santiago-and-vicinity/vicinity-santiago/cajon-del-maipo
[2] http://www.santarita.com