The Andes have a significant effect on the climate in Puente Alto. Vineyards are shaded in the morning as the sun rises over the mountain range, and warm, sunny afternoons are then followed by colder nights cooled by alpine winds. The altitude of the area exacerbates this diurnal temperature variation, slowing the ripening of the berries overnight. This leads to a balance of flavor and acidity in the wines of Puente Alto.
Vines arrived in the region in the 1800s, spreading south from the pioneering Cousifio Macul vineyard north of the Maipo River. Any description of Puente Alto as a wine-producing area must reference the great names Almaviva and Don Melchor – the two wines that put the area on the viticultural map.
Vinedo Chadwick is also based in Puente Alto and has cemented the region's prestige by winning international competitions and awards. The Berlin Tasting of 2004 pitched this Puente Alto wine against Chateaux Lafite, Latour, and Margaux and Italian greats Sassicaia and Tignanello. The panel of 36 European judges voted Viñedo Chadwick as the top wine, making history for Chile's wine industry and breaking the image of the country as a producer-only of 'good-value Merlot'.