The most significant vineyards are located in the Rio Negro Valley, where some of the most prominent Pinot Noir red wines in Argentina are made, and in the upper Neuquen Valley, especially around the town of San Patricio del Chanar. Additionally, there are promising vineyards located in the La Pampa Province near the Colorado river, near the city of 25 de Mayo. These regions have shorter summers with longer daylight hours, and significantly colder winters than the main wine areas further north.