Things To Do in Cachapoal Valley

A Copper Mine & a Nature Reserve

Close to Rancagua, El Teniente is the world's largest underground copper mine and a supremely fascinating journey into the bowels of the earth. El Teniente began in 1905 and once employed 15,000 workers, who, at the time, lived at the mine in the town Sewell (www.sewell.cl). Dubbed the "city of stairs" for its location on a mountain slope, it is now a ghost town and a UNESCO World Heritage Site, and a superb example of old company towns that fused know-how from industrialized nations with local labor. Many of the old homes have been restored as interpretive museums. About 3,000 Chileans still work at El Teniente in shifts, 24 hours a day, and a tour here puts you in safety gear and shows you how they do their job. You will be blown away by the immense size of this mine; however, claustrophobia sufferers should think twice about this tour. The minimum age is 14. VTS Tours (tel. 72/210290; www.vts.cl) has Spanish-only tours and transportation here leaving at 10:30am from the Rancagua train station.

While in the area, you'll want to pay a visit to the underrated Reserva Nacional Rio Los Cipreses, a little-known nature reserve 14km (8 3/4 miles) from Cauquenes; it's open daily from 8:30am to 6pm (until 8pm Dec-Feb); admission is $3 (£2). There is a park administration center with information, including trails and a guide to the flora and fauna of the reserve. Here it is possible to watch wild parrots swoop from trees and tiny caves high on cliffs; there are also rabbitlike vizcachas and red foxes, and, of course, a blanket of cypress trees.

You'll need your own car to get here. If you plan to stay at Termas Cauquenes (or Hacienda Los Lingues), have them plan a visit for you.