20 km from Valparaíso. Lago Peñuelas is an artificial reservoir created between 1895 and 1900 to provide drinking water to the higher parts of the cities of Valparaíso and Viña del Mar.

The reserve covers 9,260 hectares, and in the surrounding forest can be found species of plants such as quillay, peumo, litre, rosemary, brambles, musk-rose, carob, espino, etc. The forest also provides a habitat for a large number of birds and animals, including chilla and culpeo foxes, coipos, gato montés, cururos, chinchillas, egrets, patos huala, peucos, fish eagles and occasionally coscoroba swans. The lake is the largest center for water birds in the region.

The average annual temperature in this area is 14°C, and the annual rainfall is 520 mm.

The reserve is an excellent choice for those who enjoy bird-watching or fishing, or who simply want to enjoy the tranquillity of nature. There are also six picnic areas: Los Chercanes, Los Chincoles, Las Hualas, Los Patos, Las Perdices and Las Codornices.

Access from Santiago is by road in private vehicle or public transport on Ruta 68 towards Valparaíso. The highway is paved and is open all year round.