Viñales Valley, a 132 km2 (51 sq mi) karstic depression in Cuba, was added to the UNESCO World Heritage List in 1999 as a cultural landscape due to its distinctive tobacco-growing techniques. This valley, located in the Sierra de los Órganos mountains (part of Guaniguanico range) just north of Viñales in the Pinar del Río Province, is dotted with small farms and villages which have been inhabited since the era of the 'conquistadores'. The culture of the valley is a combination of indigenous peoples, African slaves, and Spanish colonizers, with traditional farming methods still used to cultivate tobacco and other crops. These methods are said to produce a higher quality tobacco than if machinery was employed.